It is time for the private sector to aid in the search for potentially city-destroying asteroids and meteors, lawmakers said during a hearing Wednesday (April 10).
The House Committee on Science, Space and Technology made the call while hearing from NASA scientists and private-sector asteroid hunters during a hearing entitled “Threats from Space,” with both groups agreeing that something more needs to be done.
“Detecting asteroids should not be the primary mission of NASA,” Rep. Lamar Smith (R-Texas), chairman of the House Committee on Science, Space and Technology, said at the hearing. “No doubt the private sector will play an important role as well. We must better recognize what the private sector can do to aid our efforts to protect the world.” [Meteor Streaks over Russia, Explodes (Photos)]
The meeting Wednesday was the second of three aimed at understanding the threat to Earth posed by asteroids in space. The first hearing took place in late March, and addressed the ways governmental entities, like NASA and the Air Force, are mitigating the risks posed by close-flying space rocks. The meetings were scheduled in response to a surprise meteor explosion over Russia and the close flyby of asteroid 2012 DA14 — both of which occurred on Feb. 15.
Astronomers have mapped the orbits of more than 90 percent of the potentially world-ending asteroids in close proximity to the Earth; however, tracking anything smaller than 0.6 miles (1 kilometer) in diameter is more difficult, said Ed Lu, the CEO of the B612 Foundation, a nonprofit organization in the early stages of building a near-Earth-object-hunting space telescope scheduled for launch in 2018.
“NASA has not even come close to finding and tracking the 1 million smaller asteroids that might only just wipe out a city, or perhaps collapse the world economy if they hit in the wrong place,” Lu said at the hearing.
B612′s space telescope, dubbed Sentinel, will be built to aid in the search for smaller asteroids near Earth. Less than 10 percent of asteroids measuring around 459 feet (140 meters) in diameter have been found, while only 1 percent of all asteroids measuring around 131 feet (40 meters) — or “city killer” range — have been tracked, Lu said.
These city-destroying asteroids are notoriously difficult to track with the ground-based methods used by NASA today because the space rocks are relatively small and dark, said Don Yeomans, the head of NASA’s Near-Earth Object Program.
“A dramatic increase in near-Earth asteroid-discovery efficiencies is achievable using space-based infrared telescopes,” Yeomans said at the hearing.
Searching for space rocks in infrared light — as the $240 million Sentinel is expected to do — could allow astronomers to find a larger number of smaller objects that are too dark to be seen in visible light, Yeomans said.
A space-based asteroid hunter is also helpful because it can seek out space rocks at all hours of the day, as opposed to just at night, Yeomans added.
All of these hunting efforts should be put in place to find near-Earth objects well before they could hit the Earth, the panelists said.
At the moment, we have the technology to deflect an asteroid, but scientists won’t be able to use those methods without ample time to implement them, Michael A’Hearn, an astronomer working with the National Research Council, said at the hearing.
But first, the asteroids have to be found, Lu said.
“You can’t deflect an asteroid that you haven’t yet tracked,” Lu said. “Our technology is useless against something we haven’t yet found.”
NASA’s bold plan to drag an asteroid into orbit around the moon may sound like science fiction, but it’s achievable with current technology, experts say.
President Barack Obama’s 2014 federal budget request, which will be unveiled today (April 10), likely includes about $100 million for NASA to jump-start an asteroid-capture mission, U.S. Senator Bill Nelson (D-FL) said last week.
The plan aims to place a roughly 23-foot-wide (7 meters) space rock into a stable lunar orbit, where astronauts could begin visiting it as soon as 2021 using NASA’s Space Launch System rocket and Orion capsule, Nelson said.
While challenging, the mission is definitely doable, said Chris Lewicki, president and chief engineer of billionaire-backed asteroid-mining firm Planetary Resources. [NASA's Asteroid-Capture Plan (Video)]
“Return of a near-Earth asteroid of this size would require today’s largest launch vehicles and today’s most efficient propulsion systems in order to achieve the mission,” Lewicki, who served as flight director for NASA’s Spirit and Opportunity Mars rovers and surface mission manager for the agency’s Phoenix Mars lander, wrote in a blog post Sunday (April 7).
“Even so, capturing and transporting a small asteroid should be a fairly straightforward affair,” Lewicki added. “Mission cost and complexity are likely on par with missions like the [$2.5 billion] Curiosity Mars rover.”
Spurring solar system exploration
NASA’s idea is similar to one proposed last year by scientists based at Caltech’s Keck Institute for Space Studies in Pasadena.
The Keck study estimated that a robotic spacecraft could drag a 23-foot near-Earth asteroid (NEA) — which would likely weigh about 500 tons — into a high lunar orbit for $2.6 billion. The returns on this initial investment are potentially huge, the researchers said.
“Experience gained via human expeditions to the small returned NEA would transfer directly to follow-on international expeditions beyond the Earth-moon system: to other near-Earth asteroids, [the Mars moons] Phobos and Deimos, Mars and potentially someday to the main asteroid belt,” the Keck team wrote in a feasibility study of their plan.
The mission would also help develop asteroid-mining technology, advocates say, and advance scientists’ understanding of how our solar system took shape more than 4.5 billion years ago.
Asteroids “probably represent samples of the earliest matter that was made available to form our solar system and our Earth,” Caltech’s Paul Dimotakis, a member of the Keck study team, told SPACE.com in February.
“We learned a lot about the moon by analyzing the moon rocks that Apollo astronauts brought back,” he added. [NASA's 17 Apollo Moon Missions in Pictures]
Asteroids are fascinating for lots of reasons. They contain a variety of valuable resources and slam into our planet on a regular basis, occasionally snuffing out most of Earth’s lifeforms. How much do you know about space rocks?
Unmanned probes have successfully rendezvoused with asteroids in deep space multiple times. Japan’s Hayabusa craft even snagged pieces of the near-Earth asteroid Itokawa in 2005, sending them back to our planet for study.
But bagging an entire asteroid and dragging it to our neck of the cosmic woods is unprecedented, and it presents several daunting challenges.
For example, the target asteroid will be spinning, which doesn’t make for a smooth ride to lunar orbit. After the spacecraft captures the asteroid and brings it into a hold of sorts, the space rock will have to be de-spun, likely with thrusters, Dimotakis said.
“You might use reaction jets to take out most of it [the spin],” he said. “You would give you yourself a lot of time to do this, because there’s no second chance in any of this.”
Further, bringing the asteroid onboard greatly increases the spacecraft’s mass, making propulsion and navigation much more difficult. And precise navigation will definitely be required to deliver the space rock to its desired orbit, Dimotakis said (though he also stressed that any asteroid chosen would pose no danger to humanity even if it somehow struck our planet).
But ion thrusters like the ones powering NASA’s Dawn mission to the huge asteroid Vesta and dwarf planet Ceres should be muscular enough to make the journey, likely taking a few years to reach the asteroid and somewhat longer to come back. And the asteroid-laden probe could probably still be guided with great care, he added.
“My guess is that all of these are not insurmountable challenges, and you would be able to calibrate yourself after you snagged it and adjust your controls,” Dimotakis said.
Choosing a target
Perhaps the biggest challenge of the entire mission is picking a suitable space rock to retrieve, Lewicki wrote in his blog post.
The Keck study recommends going after a carbonaceous asteroid packed full of water and other volatiles. Carbonaceous asteroids can be very dark, and it’s tough to spot and characterize a 23-foot asteroid in the vast depths of space whatever its color.
So both Lewicki and Dimotakis stressed the importance of searching for potential asteroid targets sooner rather than later. Planetary Resources plans to begin launching a line of small prospecting space telescopes in 2014 or 2015, and these “Arkyd-100″ craft could aid NASA’s mission, Lewicki wrote.
Dimotakis, for his part, is engaged in a follow-up to the Keck study that’s looking for potential targets in observations made by current telescopes.
“We are developing software in collaboration with JPL [NASA's Jet Propulsion Laboratory] that is going to exploit the observational digital record and essentially flag things that could be of interest and might be in this class,” he said. “This has never happened before.”
Still, mission scientists and engineers shouldn’t just sit on their hands until an asteroid selection is made, he added.
It’s important “to start developing the spacecraft before you even know where you’re going,” Dimotakis said. “If you do these things in parallel, then the mission timeline shrinks.”
Mars is farther away than any near-Earth asteroid that NASA would target, but this disadvantage may be outweighed by the greater knowledge scientists have gained of the Red Planet thanks to the many Mars missions that have launched over the years, experts say.
Further, mapping out an asteroid mission is nearly impossible at this point, since NASA does not yet know where it’s going.
“There are still no good asteroid targets for such a mission, a necessary prerequisite for determining mission length and details such as the astronauts’ exposure to radiation and the consumables required,” states a December 2012 report from the U.S. National Research Council (NRC). [How NASA Will Explore Asteroids (Gallery)]
The road to Mars
Landing astronauts on Mars has been the long-term goal of NASA’s human spaceflight program for decades, but the agency’s vision of how to get there was shaken up recently.
NASA had viewed the moon as a stepping stone, working to get humans to Earth’s natural satellite by 2020 under a program called Constellation, which was initiated during the presidency of George W. Bush. But President Barack Obama cancelled Constellation in 2010, after an independent review panel found it to be significantly under-funded and behind schedule.
instead directed NASA to send astronauts to a near-Earth asteroid by 2025, then on to the vicinity of Mars by the mid-2030s. The agency is developing a new crewed capsule called Orion and a huge rocket called the Space Launch System to make it all happen.
The new “asteroid-next” plan has not been enthusiastically embraced by NASA or the broader space community, the NRC report concluded.
“Despite isolated pockets of support for a human asteroid mission, the committee did not detect broad support for an asteroid mission inside NASA, in the nation as a whole or from the international community,” write the authors of the report, which is called “NASA’s Strategic Direction and the Need for a National Consensus.”
A tough proposition
The NRC report was based on research, interviews, site visits and analysis conducted by a 12-member independent committee over the course of about five months in 2012.
One of the people the study team met with was Bill Gerstenmaier, NASA’s associate administrator for human exploration and operations.
Gerstenmaier “talked about how NASA had discovered, in the two years that had elapsed by the time he was speaking to us, just how hard [a manned asteroid mission] was,” committee member and space policy expert Marcia Smith said during a presentation with NASA’s Future In-Space Operations working group on Jan. 30.
“He said in many respects, it’s easier to go to Mars, because we know a lot about Mars,” Smith added. “We know where it is, and we’ve done all these reconnaissance missions already, so we have a knowledge base from which to work in terms of sending humans, whereas no particular asteroid has been selected yet.”
While sending astronauts to an asteroid has never been done before, unmanned probes have successfully rendezvoused with the objects in deep space multiple times.
For example, NASA’s Dawn spacecraft orbited the protoplanet Vesta — the second-largest body in the main asteroid belt between Mars and Jupiter — for more than a year before departing to head to the belt’s largest denizen, Ceres, last September. And in 2005, Japan’s Hayabusa probe plucked some pieces off the near-Earth asteroid Itokawa, sending them back to Earth for analysis.
NASA plans to launch its own asteroid-sampling mission, called Osiris-Rex, in 2016. And two private companies — Planetary Resources and Deep Space Industries — intend to loft reconnaissance spacecraft over the next few years, kicking off an ambitious efforts to mine water, metals and other resources from asteroids.
The more stars a system of alien worlds starts with, the more likely those planets will orbit those stars at odd tilts, scientists say.
The discovery, based on a study unveiled today (Nov. 14), suggests that even Earth’s own sun may have had a companion star early in its development.
In recent years, astronomers have detected hundreds of exoplanets — worlds circling distant stars. Many of these are “hot Jupiters” — gas giants like Jupiter or Saturn that are closer to their stars than Mercury is to the sun.
Researchers had thought hot Jupiters arose when giant planets were dragged inward by protoplanetary disks of gas and dust falling toward stars. However, this idea was recently cast into doubt by the surprising discovery that a major fraction of hot Jupiters have orbits that are tilted in respect to their stars’ rotation.
Stars all spin, just as Earth’s does, and their worlds often line up with this spin — they orbit around the equators of their stars and revolve in the same direction. However, sometimes alien planets have misaligned orbits instead, ones that are at slight or even sharp angles around their stars. The orbits of some exoplanets are so far tilted that they are actually backwards — they move in retrogradeorbits in exactly the opposite direction of their stars’ spin.
Scientists had thought if hot Jupiters were dragged toward their stars by protoplanetary disks, they would all end up in relatively normal orbits around the equators of their stars. However, astronomers recently discovered that a whopping 25 to 50 percent of these planets actually may have misaligned orbits.
“The misalignments seemed to point towards a much more volatile, violent evolutionary path for hot Jupiters,” said study author Konstantin Batygin, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics.
For instance, perhaps it was a gravitational tug of war between exoplanets that hurled some inward at their stars. Still, it seemed unlikely such processes were responsible for all these misaligned planets.
“A crude and oversimplified analogy is taking a machine gun, shooting in every direction possible, and hitting the correct target about 1 percent of the time,” Batygin said. “Surely not impossible, but it seems unlikely.”
Now Batygin has discovered protoplanetary disks can indeed produce such tilted orbits if these systems each harbored multiple stars. [Photos: Alien Planet With Twin Suns Found]
Although the solar system has only one sun, most stars like Earth’s sun are binaries— two stars orbiting each other as a pair. Increasingly, astronomers are discovering planetary systems with twin suns (like Luke Skywalker’s fictional home planet Tatooine in “Star Wars”). There are also many three-star triples in the universe, at least one of which is known to host planets, and the number of stars a system has can even climb as high as seven.
Through computer modeling, Batygin found that the complex system of gravitational pulls that binary stars exert on protoplanetary disks would disrupt them enough to misalign the disks. He added that the more stars a system has, the more likely its planets orbits would be tilted.
This idea does not require that a system have multiple stars for billions of years, Batygin added.
“It is generally believed that 85 to 100 percent of stars form as multiples,” he said. Many times, stars then get stripped from these systems during the first 1 million to 10 million years of their lifetimes.
Batygin noted the orbital plane of the solar system’s planets is misaligned from the sun’s equatorial plane by 7 degrees. Given this skew, “I think it is safe to say that the solar system falls into the misaligned category.” In other words, the sun once may have had a companion star very early in its history.
Future research can analyze other details about the interactions between planets, their stars and protoplanetary disks. “For instance, the magnetic coupling between the disk and the host star should be looked at more carefully,” Batygin said.
Batygindetails his findings in the Nov. 15 issue of the journal Nature.
Amateur astronomers have helped discover an alien planet with two suns and a twinkling twist: The entire twin-sun setup, a real-life version of Tatooine from “Star Wars,” is orbited by two more stars — a solar system that is the first of its kind known.
The alien planet, called PH1, is a gas giant planet slightly bigger than Neptune. Its discovery in the midst of a strange, four-star planetary system is the first confirmed world discovered as part of the Yale University-led Planet Hunters project, in which armchair astronomers work with professional scientists to find evidence of new worlds in the bountiful data collected by NASA’s Kepler space telescope.
“Planet Hunters is a symbiotic project, pairing the discovery power of the people with follow-up by a team of astronomers,” said Debra Fischer, a professor of astronomy at Yale and planet expert who helped launch Planet Hunters in 2010, in a statement. “This unique system might have been entirely missed if not for the sharp eyes of the public.”
Since its March 2009 launch, Kepler has found evidence of more than 2,300 candidate alien worlds. [Gallery: More Alien Planets with Twin Suns]
Finding a strange, new world
Since its initial discovery via Planet Hunters, the existence of PH1 has been confirmed by a team of professional astronomers, who will present their work today (Oct. 15) at the annual meeting of the Division for Planetary Sciences of the American Astronomical Society in Reno, Nev.
With a radius about 6.2 times that of Earth’s, PH1 is a smidge bigger than Neptune. The gassy planet spends 138 days completing a single orbit around its two parent stars, which have masses about 1.5 and 0.41 times that of the sun. The stars circle each other once every 20 days.
The two other stars orbiting the PH1′s twin suns are about 1,000 astronomical units (AU) from the parent stars. (One AU is about the distance between the Earth and sun, about 93 million miles or 150 million kilometers.)
If you’re hoping to catch the quadruple sunset, this may not be your best bet. The researchers estimate PH1′s temperature would range from a minimum of about 484 degrees Fahrenheit (524 Kelvin, or 251 degrees Celsius) and a maximum of 644 degrees F (613 Kelvin, or 340 degrees C), too hot to be in the habitable zone.
“Although PH1 is a gas giant planet, even if there is a possibility of rocky moons orbiting the body, their surfaces would be too hot for liquid water to exist,” researcher Meg Schwamb of Yale University and colleagues write in a draft of their research article.
Alien Planet Quiz: Are You an Exoplanet Expert?
Astronomers have confirmed more than 700 planets beyond our own solar system, and the discoveries keep rolling in. How much do you know about these exotic worlds?
A planet with two suns
Until now, scientists had identified just six planets orbiting two parent stars, called circumbinary planets, and none of these have stellar companions orbiting them. Until their discovery, circumbinary planets were once the realm of science fiction with Tatooine, the fictional homeworld of Luke Skywalker in “Star Wars,” among the most famous.
“Circumbinary planets are the extremes of planet formation,” Schwamb said in a statement. “The discovery of these systems is forcing us to go back to the drawing board to understand how such planets can assemble and evolve in these dynamically challenging environments.”
The Planet Hunter volunteers, Kian Jek of San Francisco, Calif., and Robert Gagliano of Cottonwood, Ariz., spotted PH1 using the transit method, noticing faint dips in light as the plant passed in front of, or transited, its parent stars.
Gagliano said he was “absolutely ecstatic” about the finding. “It’s a great honor to be a Planet Hunter, citizen scientist, and work hand in hand with professional astronomers, making a real contribution to science,” he said.
Jek, too, expressed his amazement.
“It still continues to astonish me how we can detect, let alone glean so much information, about another planet thousands of light-years away just by studying the light from its parent star,” he said in a statement.
Schwamb led the team of professional astronomers who confirmed the discovery and characterized the planet, following observations from the Keck telescopes on Mauna Kea, Hawaii.
The research was supported by NASA and the National Science Foundation Astronomy and Astrophysics Postdoctoral Fellowship.
The discovery of the first alien planet with two suns — like the “Star Wars” world Tatooine — residing in its parent star’s habitable zone is good news for the search for life beyond Earth, scientists say.
The planet, known as Kepler-47c, is a gas giant and therefore probably not suitable for life as we know it. But its existence hints that smaller, rockier worlds may inhabit other two-star systems’ habitable zones —that just-right range of distances where liquid water can exist.
And that’s important, because there are a lot of binary systems out there, scientists say.
“Roughly half of the stars in the galaxy are in binary systems,” study lead author Jerome Orosz, of San Diego State University, told SPACE.com. “I thought it would only be a matter of time before we found a system like Kepler-47 where a planet is in the habitable zone.” [Gallery: The Tatooine-Like Kepler-47 System]
The Kepler-47 system, whose discovery was announced Tuesday (Aug. 28), dwells about 5,000 light-years away, in the constellation Cygnus (The Swan). It is a close binary system, with two stars orbiting near each other at its center. Around these stars whirl two planets known as Kepler-47b and Kepler-47c.
They make Kepler-47 the first system seen with multiple worlds circling a pair of stars.
“If single stars and close binary stars can host planetary systems with an equal probability — that is not at all clear at the moment — then it would follow that life could be just as common on circumbinary planets as on planets with single stars,” Orosz said.
Kepler-47c, which appears to be slightly larger than Uranus, is the outer world. It takes the planet 303 days to complete an orbit, placing it squarely in the system’s habitable zone. (Kepler-47b is a bit smaller than its planetary sibling but much closer-in, making it likely too hot to host life.)
Kepler-47c itself is likely not a good bet to support life. But any large moons of the planet — if they exist — would be very intriguing to astrobiologists, said study co-author William Welsh at San Diego State University.
Scientists have already found several exoplanets that are Earth-size or smaller, and they hope to discover many more. NASA’s prolific Kepler space telescope, which discovered Kepler-47b and c, is a key tool in this search.
Indeed, Kepler’s main mission is to determine just how commonly Earth-size planets occur in their stars’ habitable zones throughout the galaxy. The telescope detects alien planets by flagging the telltale brightness dips caused when they cross in front of, or transit, their stars’ faces from the instrument’s perspective..
“I expect that the transits of an Earth-sized planet will be very hard to spot by eye, so we will need to refine our automated search programs to work for binary systems,” Orosz said. “As Kepler gets more and more data, the chances go up that we can identify the smaller transits due to terrestrial planets.”
The scientists published their findings online Aug. 28 in the journal Science. They also detailed their results Aug. 29 at the General Assembly of the International Astronomical Union in Beijing.
Fleeing from the scene of a violent supernova explosion, a compact runaway star may be the fastest traveling pulsar yet discovered, scientists say. The small but powerful star is rushing away from the source of the blast almost 25 times faster than most similar objects move.
When the dust clears from a supernova, the outer layers of the dying star blow into space, leaving behind a neutron star, which is a city-sized object with a mass comparable to the sun.
“In a lot of cases, when the neutron star is not moving fast, you’ll find it right in the middle of the supernova remnant,” John Tomsick of the University of California, Berkeley, told SPACE.com.
Not so for IGR J11014-6103, a special type of rotating neutron star known as a pulsar. The explosion that created this object came with a kick that sent it flying away from its birth location at blistering speeds of between 5.4 and 6.5 million miles per hour.
According to Tomsick, most neutron stars travel anywhere between 225,000 to a mph (100 to 600 kilometers per second), with only a few exceeding 2.2 million mph (1,000 km/s). [Supernova Photos: Great Images of Star Explosions
An uneven explosion
In order for a neutron star to travel after a supernova, there must be some kind of push created by the stellar death, the researchers said. In a symmetrical explosion, the forces pressing on the new neutron star cancel each other out, and the star remains in the center, where the initial explosion occurred.
But if there is any type of asymmetry in the explosion, the stronger force imparts a kick to the compact star, sending it flying through space.
Scientists are still uncertain what causes these asymmetric explosions. Tomsick explained that there could be a correlation between the magnetic field of the neutron star and its strong kick, but nothing conclusive has been demonstrated yet.
Tomsick hopes that a closer look at the atypical IGR J10014-6103 pulsar could shed some light on the mystery.
“If we found that this neutron star had a high magnetic field, it would provide some evidence that it’s related to the velocity,” he said.
Lying in a bed of dust and gas about 30,000 light-years away from Earth, the energetic source first turned up in a survey of hard X-ray objects by the European Space Agency’s Integral satellite. Tomsick and his team have performed follow-up studies of several of Integrals’ new objects.
Initially, nothing about IGR J10014-6103 stood out. But, after examining the object using NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton satellite, as well as the Parkes radio telescope in Australia, they realized a tail 3 light-years long trailed behind the source.
“When (the neutron star) plows through, it accelerates the particles that are in the interstellar medium,” Tomsick said.
This creates a bow shock effect, much like a boat breaking through water. A slow-moving star forms a wider shock, while a fast-moving star produces a narrow one, such as the one formed by IGR J10014-6103.
A curious pulsar
Knowing that the supernova is 15,000 years old, and logging the distance the neutron star had traveled in that time, Tomsick and his team were able to calculate its speed.
Pulsars are a special type of neutron star that rotates rapidly, emitting a beam of high-energy that spins much like the bulb in a lighthouse. But astronomers have not yet been able to actually detect this signature beam from IGR J10014-6103.
According to Tomsick, the radio emission from the gas and dust surrounding the star make those pulses more difficult to read. In fact, the only way the pulses could have been seen with the current observations would be if the flashing neutron star was excessively bright.
“It could be a typical pulsar, and we still wouldn’t be able to detect it,” Tomsick said.
But the scientists are confident the object is a pulsar, rather than a regular neutron star, because of its high-energy emission and the fact that it doesn’t show up in optical wavelengths. They intend to do more in-depth observations of the object in the near future, searching for details about its pulsation and its magnetic field.
“If we do a study in X-rays and still don’t see pulsation, then we’ll be pretty surprised.”
Detailed results of the study were published in the May edition of the Astrophysical Journal Letters.
A surprising number of massive stars in our Milky Way galaxy are part of close stellar duos, a new study finds, but most of these companion stars have turbulent relationships — with one “vampire star” sucking gas from the other, or the two stars violently merging to form a single star.
Astronomers using the European Southern Observatory’s Very Large Telescope in Chile studied massive O-type stars, which are very hot and incredibly bright. These stars, which have surface temperatures of more than 54,000 degrees Fahrenheit (30,000 degrees Celsius) live short, violent lives, but they play key roles in the evolution of galaxies.
The researchers discovered that more than 70 percent of these massive stars have close companions, making up so-called binary systems in which two stars orbit each other.
While this percentage is far more than was previously expected, the astronomers were more surprised to find that majority of these stellar pairs have tumultuous relationships with one another, said study co-author Selma de Mink, of the Space Telescope Science Institute in Baltimore.
“We already knew that massive stars are very often in binaries,” de Mink told SPACE.com. “What is very surprising to us is that they’re so close, and such a large fraction is interacting. If a star has a companion so close next to it, it will have a very different evolutionary path. Before, this was very complicated for us to model, so we were hoping it was a minority of stars. But, if 70 percent of massive stars are behaving like this, we really need to change how we view these stars.” [Top 10 Star Mysteries]
Studying stellar behemoths
Type O stars drive galaxy evolution, but these stellar giants can also exhibit extreme behavior, garnering the nickname “vampire stars” for the way they suck matter from neighboring companions.
“These stars are absolute behemoths,” study lead author Hugues Sana, of the University of Amsterdam in the Netherlands, said in a statement. “They have 15 or more times the mass of our sun and can be up to a million times brighter.”
These massive stars typically end their lives in violent explosions, such as core-collapse supernovas or gamma-ray bursts, which are so luminous they can be observed throughout most of the universe.
For the new study, the astronomers analyzed the light coming from 71 O-type stars — a mix of single and binary stars — in six different star clusters, all located roughly 6,000 light-years away.
The researchers found that almost three-quarters of these stars have close companions. Most of these pairs are also close enough to interact with one another, with mass being transferred from one star to the other in a sort of stellar vampirism. About one-third of these binary systems are even expected to eventually merge to form a single star, the researchers said.
The results of the study indicate that massive stars with companions are more common than was once thought, and that these heavyweights in binary systems evolve differently than single stars — a fact that has implications for how scientists understand galaxy evolution.
“It makes a big difference for understanding the life of massive stars and how they impact the whole universe,” said de Mink.
Big stars with a big impact
Type O stars make up less than 1 percent of the stars in the universe, but they have powerful effects on their surroundings. The winds and shocks from these stars can both trigger and halt star formation processes, the researchers said.
Over the course of their lives, culminating in the supernova explosions that signal their death, these massive stars also produce all the heavy elements in the universe. These elements enrich galaxies and are crucial for life.
But for massive stars in close binary systems, the interactions between the pair impact the evolution of both stars.
With vampire stars, the lower-mass star sucks fresh hydrogen from its companion, substantially increasing its mass and enabling it to live much longer than a single star of the same mass would, the researchers explained. The victim star, on the other hand, is left with an exposed core that mimics the appearance of a much younger star.
These factors could combine to give researchers misleading information about galaxies and the stars within them.
“The only information astronomers have on distant galaxies is from the light that reaches our telescopes,” said Sana. “Without making assumptions about what is responsible for this light, we cannot draw conclusions about the galaxy, such as how massive or young it is. This study shows that the frequent assumption that most stars are single can lead to wrong conclusions.”
The hunt is on. A group of scientists has banded together to build the world’s first privately funded deep-space telescope, to hunt for asteroids that could pose a major threat to Earth.
The private space telescope forms the heart of Project Sentinel, a deep-space mission being unveiled today (June 28) in Mountain View, Calif., by the B612 Foundation, a nonprofit group of scientists and explorers that has long advocated the exploration of asteroids and better space rock monitoring.
Project Sentinel involves the development of a super-snooper telescope that would be placed in orbit around the sun. The goal, foundation officials say, is to create the first comprehensive dynamic map of our inner solar system.
That map would yield a lively look at the present and future locations and trajectories of near-Earth asteroids, paving the way to protecting the Earth from future impacts and opening the solar system to future exploration. [Sentinel Space Telescope's Asteroid Mission (Pictures)]
An asteroid sentinel in space
Ed Lu is B612 chairman and CEO, a former NASA astronaut who has flown on the space shuttle and Russia’s Soyuz capsule and lived aboard the International Space Station.
“The reason we’re doing this is because we can!”Lu told SPACE.com
Private organizations can now carry out awe-inspiring and audacious projects that previously only governments could accomplish, Lu said.
“So it isn’t crazy to think of a large telescope being funded privately. In fact, historically, that has been the way large, private telescopes here on Earth have been funded. The exception here is that rather than being on the Earth, this one is orbiting the sun,” Lu said.
A lot of work has gone into shaping Project Sentinel over the last year, Lu said. Akin to the architectural plans for a building, he said, a preliminary spacecraft and mission design is complete.
“This isn’t a viewgraph,” Lu added.”What we’ve built is the best technical team on this planet.”
A firm fixed-price proposal to carry out Project Sentinel has been submitted by Ball Aerospace of Boulder, Colo., enabled in part by early infrared-detector work funded by B612.
No stranger to big space scopes, Ball Aerospace is the technical sparkplug behind such NASA-sponsored spacecraft as theplanet-hunting Kepler mission and the infrared Spitzer Space Telescope.
Under a NASA Space Act Agreement signed with B612, the space agency will provide Deep Space Network communications and tracking as well as technical support.
Return To PollHunting asteroids for all mankind
Project Sentinel would complete its near-Earth object (NEO) survey work in 5.5 years.
“The line in the sand is for the spacecraft to find 90 percent of near-Earth objects larger than 140 meters [459 feet] in size. That translates into approximately a 100-megaton explosion should one hit the Earth,” Lu said. “If we go as long as we think we’re going to go, we’re also going to find the vast majority of Tunguskas, too.” [7 Strangest Asteroids in the Solar System]
The Tunguska River in remote Siberia was the site directly under a huge explosion in 1908, an air burst of a large meteoroid or comet fragment estimated to have flattened more than 80 million trees over 830 square miles (2,150 square kilometers).
According to B612, only about 10,000 of the more than half million asteroids larger than the 1908 Tunguska asteroidwhose orbits cross Earth’s orbit have been discovered and tracked.
Project Sentinel would find and road-map Earth-bound asteroids with sufficient warning time – years to decades – to enable deflection missions.
This all adds up to an awe-inspiring project for the global good, the B612 NEO team said.
Space telescope price tag
What’s the cost to build the Project Sentinel telescope?
“We can’t disclose the final price, but I can give you a ballpark of a few hundred million dollars. Which is, I think, a factor of several less than what NASA could do this for,” Lu said.
To foot the bill for Project Sentinel, a worldwide fundraising campaign is being implemented, including outreach to citizens around the globe.
“Our constituency is everybody,” said B612 spokeswoman Diane Murphy.
“If you think about it, what we are is a small capital campaign,” Lu said. “At any given time in the United States, there’s probably a hundred fundraising campaigns larger than this … for symphony halls, museums, performing arts centers.”
Data pipeline set
As now forecast, Project Sentinel would be launched in 2016 aboard a SpaceX Falcon 9 rocket, Lu said. The spacecraft operations center is to be based at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado, Boulder.
Project Sentinel would require a gravity slingshot off Venus to enter solar orbit. Data relay would be carried out through the NASA Deep Space Network. Data analysis — identification of NEO threats — is to be handled through an existing data pipeline at the Minor Planet Center in Cambridge, Mass., and the NASA Jet Propulsion Laboratory in Pasadena, Calif.
“When you stand back from this, … this is like the whole issue of mapping the U.S, and almost everything else that precedes real development and exploration,” said former astronaut Rusty Schweickart, B612 chairman emeritus, who was the lunar module pilot on the Apollo 9 mission.
“The meta-view of what we’re doing … is mapping the Earth, sun, the inner solar system … the Earth Territory, if you will,” Schweickart said. That, he said, would pave the way toward protecting the Earth from impacts and opening the solar system to exploration.
Legacy space systems
“An exciting aspect of Ball’s role on Sentinel is leveraging sophisticated technology developed under the Deep Impact, Spitzer, and Kepler missions for the B612 Foundation,” said John Troeltzsch, the company’s Sentinel Program manager.
Troeltzsch told SPACE.com the aerospace firm will reuse deep-space elements the company helped pioneer. For the privately funded mission, that could include the science-downlink technology flown on Kepler and the cryogenic thermal-isolation system from the Spitzer Space Telescope.
The Sentinel ground system will build on the system in daily use by the Kepler mission, which is supplied to Ball by the LASP at Colorado-Boulder.
“Ball has been working on the mission concept for a NEO survey mission like Sentinel since 2005. This has allowed us to refine and iterate the design to a state of maturity that supports a commercial offering to B612,” Troeltzsch said. “Although there are challenges in front of us, like the development of the focal plane detectors, the overall system is based on proven, high-heritage systems.”
Troeltzsch said it’s not every day you can have fun working on a powerful space telescope and help protect the planet at the same time.
“Sooner or later one of the NEOs that Sentinel will discover will end up on a collision course with the Earth. I am sure that my kids and grandkids will appreciate the foresight B612 has shown in sponsoring this mission to help protect us all,” Troeltzsch concluded.
Big, bad Jupiter likely squashed any chance the giant asteroid Vesta may have had of growing into a full-fledged planet long ago, researchers say.
Scientists analyzing observations from NASA’s Dawn spacecraft announced on (May 10) that the enormous asteroid Vesta is actually an ancient protoplanet, a planetary building block left over from the solar system’s earliest days.
Many other Vesta-like objects were incorporated into rocky worlds such as Earth, but Vesta’s development along this path was halted.
Vesta’s stunted growth is chiefly a product of its location, researchers said. The protoplanets that glommed together to form Mercury, Earth, Mars and Venus did so in the inner solar system, relatively far from the disruptive gravitational influence of a giant planet.
The 330-mile-wide (530-kilometer) Vesta, on the other hand, grew up in the main asteroid belt between Mars and Jupiter. And the solar system’s largest planet made it tough for Vesta to hook up with others of its kind.
“In the asteroid belt, Jupiter basically stirred things up so much that they weren’t able to easily accrete with one another,” Dawn scientist David O’Brien, of the Planetary Science Institute in Tucson, Ariz., told reporters today.
“The velocities in the asteroid belt were really high, and the higher the velocity is, the harder it is for things to merge together under their own gravity,” O’Brien added.
Those high velocities also set the stage for some incredibly violent collisions, which probably destroyed a fair number of Vesta-like bodies. Vesta itself was battered and bloodied by some huge impacts; one crater near its south pole is 314 miles (505 km) wide, and another underneath that one measures 250 miles (400 km) across.
So while Vesta — the second-largest denizen of the asteroid belt — was doomed to a life of solitude, it has had the toughness and luck to stick around for the last 4.5 billion years. And scientists are thankful that it did.
“Vesta is special, because it survived the intense collisional environment of the main asteroid belt for billions of years, allowing us to interrogate a key witness to the events at the very beginning of the solar system,” said Dawn deputy principal investigator Carol Raymond, of NASA’s Jet Propulsion Laboratory in Pasadena, Calif.
“We believe Vesta is the only intact member of a family of similar bodies that have since perished,” she added.
Science fiction dreams of mining riches from asteroids only make sense if humans can make it worth their time and effort. The new Planetary Resources group backed by Silicon Valley billionaires and Hollywood moguls is now betting on the fact that there is big money in mining space rocks.
Nobody knows exactly how much asteroid wealth exists, but early estimates point to riches beyond Earth’s wildest dreams. Just the mineral wealth of the asteroid belt between the orbits of Mars and Jupiter could be equivalent to about $100 billion for every person on Earth, according to “Mining the Sky: Untold Riches from the Asteroid, Comets, and Planets” (Addison-Wesley, 1996) — perhaps slightly less now after accounting for the Earth’s population growth over the past 15 years. [Does Asteroid Mining Violate Space Law?]
“The near-Earth asteroid population could easily support 10 to 40 times the population of Earth, with all the necessary resources to do that,” said John Lewis, a professor emeritus at the Lunar and Planetary Laboratory of the University of Arizona and author of “Mining the Sky.”
Even smaller space rocks can have mineral prizes worth tens of trillions of dollars. The smallest known metallic asteroid that is an accessible near-Earth object has 40 times as much metal as all the metal in Earth’s history, Lewis pointed out. He has joined Planetary Resources as perhaps the most recognized expert on asteroid wealth.
There’s platinum in thar rocks
Knowing what asteroid wealth consists of depends on incomplete but enticing scientific surveys. Scientists sitting on Earth can detect chemical signatures of asteroids based on reflected light, or directly sample space rocks fallen to Earth as meteoroids. Japan has carried out the only successful space mission to retrieve asteroid samples in space, but the U.S. is planning its own asteroid sample and retrieval missions.
An M-class asteroid about 79-feet (24-meter) long could have as much as 33,000 tons of extractable metal and possibly one ton of platinum group metals. The platinum alone could be easily worth about $50 million dollars in Earth’s commodity markets, according to studies cited by the paper “Assessment on the feasibility of future shepherding of asteroid resources” in the April-May issue of the journal Acta Astronautica.
Such platinum-group metals represent the main prize for Earth markets, said Joan-Pau Sanchez, a researcher in the Advanced Space Concepts Laboratory at the University of Strathclyde in the UK. He coauthored the Acta Astronautica paper.
“Platinum-group metals (PGMs) are likely to be the only material from asteroids that will prove economically viable to be transported back to Earth’s commodity markets,” Sanchez told InnovationnewsDaily. “PGMs are in high demand, and will be even more in the future.”
Turning space rocks into riches
But the Planetary Resources group has its eyes on more than just platinum to strike it rich, Lewis said. He described using asteroid metals to build huge space stations or even space solar power stations for beaming energy down to Earth.
That could come from the abundant S-class asteroids — about 40 percent of the near-Earth objects — which hold metals, semiconductors, and even oxygen or water. One 79-foot (24-meter) asteroid of the S-class could provide 1,100 to 4,400 tons of iron for building the structural support for a huge solar array capable of making a gigawatt of power (as much as a large power plant) for either space stations or Earth, according to the Acta Astronautica paper.
A similar-size hydrated carbonaceous asteroid could hold a million liters of water (enough to fill half a million soft drink bottles). That would fall under the second big market envisioned by Planetary Resources — harvesting asteroid resources for use as rocket propellants, drinking water and oxygen to support space exploration missions.
“The billionaires who are standing behind this right now are not doing this for fun and recreation,” Lewis said. “They see it as a great economic value in the long run, and I’m not surprised if more than one wants to make a dime out of it.”
A NASA spacecraft orbiting the huge asteroid Vesta has snapped amazing new photos of the colossal space rock, images that reveal strange features never-before-seen on an asteroid, scientists say.
The new photos of Vesta from NASA’s Dawn spacecraft highlight odd, shiny spots that are nearly twice as bright as other parts of the asteroid — suggesting it is original material left over from the space rock’s birth 4 billion years ago, NASA officials said today (March 21).
With a width of about 330 miles (530 km), asteroid Vesta is one of the largest and brightest objects in the main asteroid belt between the orbits of Mars and Jupiter. NASA’s Dawn probe has been orbiting Vesta since 2011 to study the space rock in unprecedented detail.
“Our analysis finds this bright material originates from Vesta and has undergone little change since the formation of Vesta over 4 billion years ago,” said Jian-Yang Li, a Dawn participating scientist at the University of Maryland, College Park, in a statement. “We’re eager to learn more about what minerals make up this material and how the present Vesta surface came to be.”
Asteroid Vesta unveiled
Li and his colleagues unveiled Dawn’s new views of Vesta today at the 43rd Lunar and Planetary Science Conference in The Woodlands, Texas.
The photos show surprisingly bright spots all over Vesta, with the most predominant ones located inside or around the asteroid’s many craters. The bright areas range from large spots (around several hundred feet across) to simply huge, with some stretching across 10 miles (16 kilometers) of terrain. [Video: Vesta — Asteroid or Dwarf Planet?]
“Dawn’s ambitious exploration of Vesta has been going beautifully,” said Marc Rayman, Dawn chief engineer at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., which oversees the mission. “As we continue to gather a bounty of data, it is thrilling to reveal fascinating alien landscapes.”
Dawn mission scientists suspect the bright patches on Vesta were exposed during violent collisions with other space rocks. These impacts may have spread the bright material across the asteroid and mixed it together with darker material on Vesta’s surface, researchers said.
Astronomers have known about variations in Vesta’s brightness for some time. Photos taken by the Hubble Space Telescope before Dawn arrived at the asteroid also revealed the bright patches.
Never-before seen asteroid melt
But only the close-up photos from the Dawn probe have revealed the surprising variety of dark blotches on Vesta, which appear as dark gray, brown or reddish blemishes, NASA officials said.
In some views, these darker spots are small deposits near impact craters, while in other photos they appear in larger concentrations. These darker spots on Vesta may also be the result of collisions on the asteroid, researchers said.
Slow carbon-rich asteroids may have created some of the smaller dark material deposits without carving out a big crater. Meanwhile, faster objects may have potentially slammed into Vesta so hard they melted the big asteroid’s crust, which could have also created the dark spots.
“Some of these past collisions were so intense they melted the surface,” said Brett Denevi, a Dawn participating scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. “Dawn’s ability to image the melt marks a unique find. Melting events like these were suspected, but never before seen on an asteroid.”
NASA launched the $466 million Dawn spacecraft in 2007 and Vesta is only the first stop of the spacecraft’s two-asteroid tour. Dawn arrived at Vesta in July 2011 and is expected to spend about a year there before heading off to its next target — the even larger asteroid Ceres, which is also classified as a dwarf planet.
Dawn is expected to arrive at Ceres in February 2015.
These bubbles are blown by young, hot stars into the surrounding gas and dust, and indicate areas of brand-new star formation, scientists say.
“These findings make us suspect that the Milky Way is a much more active star-forming galaxy than previously thought,” Eli Bressert, an astrophysics doctoral student at the European Southern Observatory, said in a statement. “The Milky Way’s disk is like champagne with bubbles all over the place.”
About 35,000 volunteers sifted through data from NASA’s Spitzer Space Telescope on the online Milky Way Project to make the discoveries. These citizen scientists have found about 10 times more bubbles than previous surveys. [See the space bubbles]
In this case, human eyes are very good at spotting what computer programs often miss. The volunteers were able to identify partially broken rings and overlapping bubbles that would have confused algorithms. To make sure the volunteers identify likely bubbles, the program requires each candidate bubble to be flagged by five participants before it’s added to the catalog.
“The Milky Way Project is an attempt to take the vast and beautiful data from Spitzer and make extracting the information a fun, online, public endeavor,” said principal investigator of the Milky Way Project Robert Simpson, a postdoctoral researcher in astronomy at Oxford University in England.
Astronomers hope to use this collection of cosmic bubbles to study star formation in the galaxy. The results are already turning up some surprises, such as the fact that bubbles seem to be less common on either side of the galactic center.
“We would expect star formation to be peaking in the galactic center because that’s where most of the dense gas is,” Bressert said. “This project is bringing us way more questions than answers.”
Scientists at Los Alamos National Laboratory, a United States Department of Energy facility in New Mexico, used a supercomputer to model nukes’ anti-asteroid effectiveness. They attacked a 1,650-foot-long (500-meter) space rock with a 1-megaton nuclear weapon — about 50 times more powerful than the U.S. blast inflicted on Nagasaki, Japan, to help end World War II.
The results were encouraging.
“Ultimately this 1-megaton blast will disrupt all of the rocks in the rockpile of this asteroid, and if this were an Earth-crossing asteroid, would fully mitigate the hazard represented by the initial asteroid itself,” Los Alamos scientist Bob Weaver said in a recent video released by the lab. [Video: Nuclear bomb takes out asteroid]
In the 3-D modeling study, run on 32,000 processors of the Cielo supercomputer, the blast went off at the asteroid’s surface. So the nuke likely wouldn’t have to be deposited deep into a threatening space rock, a dangerous job Bruce Willis and his astronaut crew tackled in the 1998 film “Armageddon.”
Weaver stressed that nuclear bombs would likely be deployed only as a last resort, if an impact loomed just months away. And other researchers caution that a nuclear blast might have negative side effects, such as sending a hail of many small space rocks toward Earth instead of a single big one.
If humanity had more notice of an impending impact, there are several other asteroid defense strategies we might be able to employ, scientists have said.
For example, we could send a robotic probe out to rendezvous and ride along with the potentially dangerous asteroid. The spacecraft’s modest gravity would exert a tug on the space rock as the two cruise through space together. Over months or years, this “gravity tractor” method would pull the asteroid into a different, more benign orbit.
We have the know-how to pull off such a mission. Multiple probes have met up with rocks in deep space, including NASA’s Dawn spacecraft, which is currently orbiting the huge asteroid Vesta. And in 2005, Japan’s Hayabusa probe plucked some pieces off the asteroid Itokawa, sending them back to Earth for analysis.
Humanity could also simply slam the rendezvous craft into the asteroid, relying on brute force rather than a gentle gravitational tug to push it off course. This impactor approach would not be as precise as the gravity tractor technique, researchers say, but it could still do the job under certain circumstances.
We’ve demonstrated the ability to accomplish this more aggressive mission as well. In 2005, for example, NASA sent an impactor barreling into the comet Tempel 1 to determine the icy object’s composition.
Discussions about asteroid deflection aren’t just academic exercises. Huge impacts are a part of our planet’s history; one wiped out the dinosaurs 65 million years ago, and it’s just a matter of time before another big space rock lines Earth up in its sights, astronomers say.
Asteroid 2012 DA14 is making headlines this week, despite the fact that the “incoming” space rock, as it has been described, definitely won’t hit Earth.
The 150-foot-wide space rock will pass within 17,000 miles (27,000 kilometers) of us next February. That’s nearer than the orbits of some geosynchronous satellites, and the closest shave of a mid-size asteroid ever predicted before the actual flyby has occurred. But even so, NASA assures the world that there is no chance of asteroid 2012 DA14 hitting Earth next year. Zero, zip, zilch.
Why, then, all the terror about this unthreatening space rock? And why the recent doom and gloom about another space rock, the big asteroid 2011 AG5, a football-field-size rock that NASA says will almost certainly not collide with the planet in 2040? Don Yeomans, head of the Near-Earth Object Observations Program at NASA’s Jet Propulsion Laboratory, blames the upsurge in asteroid panic on two main factors.
“One problem is that the Internet is wide open to anyone to say anything,” Yeomans told Life’s Little Mysteries, a sister site to SPACE.com. In the past, claims about asteroids were written up by scientists and submitted to peer-reviewed journals, a critical process that “would filter out nonsense,” he said. “If something was published, it was reliable.”
But today, hundreds of scary blurbs about the latest asteroid get written and posted to blogs and tabloid-like sites before NASA scientists can vet the claim and publish their official, less-terrifying statement regarding the asteroid’s trajectory.
“In the case of this asteroid, you get hundreds of hits on the Internet, and in the case of the 2012 [Mayan calendar] business, millions of hits suggesting disaster. And you get a few folks in the media and at NASA who put out the truth. But people go online and see millions about disasters and a few saying ‘no disaster’ and they think, well, the majority of these say I should be worried,” Yeomans said. [When Space Attacks: 6 Craziest Meteor Impacts]
The other half of the problem is that many people do not know how to judge the validity of the pseudo-scientific information they read. “There are millions of people out there who have not been trained in the scientific method, and don’t understand that evidence is critical for supporting any new idea — especially any dramatic departure from the current state,” he said.
In psychology, this is known as the Dunning-Kruger effect. People who lack knowledge in a given area, such as science, are unable to accurately assess their own abilities in that area, and so they aren’t aware that they are coming to blatantly false conclusions.
David Dunning, a psychologist at Cornell University who first characterized the phenomenon, recently explained, “Many people don’t have training in science, and so they may very well misunderstand the science. But because they don’t have the knowledge to evaluate it, they don’t realize how off their evaluations might be.”
There is no obvious remedy for the one-two punch of widespread misinformation and a lack of mental tools for evaluating it, but Yeomans said scientists need to do a better job engaging with the public. He and his group regularly address people’s fears regarding near-Earth asteroids by making statements and issuing news releases.
“The hope is that people will understand that we are the more trusted sources of information,” Yeomans said.
And in the case of 2012 DA14, the information is this: There is zero chance of the asteroid hitting Earth next year. The chance of a collision is slightly higher — 1 in 80,000 — when it swings past in 2020, but radar and optical observations of the space rock during next year’s flyby will help the scientists nail down its trajectory, which will in all likelihood reduce the 2020 risk estimate to zero.
There are better things to worry about even than the absolute worst-case scenario. If observations next year show that current estimates are way off and the asteroid and Earth are on track to collide in 2020, then NASA would try to deflect it by bumping it with a space probe sometime before then — a move Yeomans says is doable.
Even if that failed, any Earthbound asteroid has a 70 percent chance of plunging into the ocean, and a much higher chance still of impacting only an ocean or an unoccupied land region.
An asteroid this size strikes Earth every 700 years or so, Yeomans said. Humanity has survived innumerable such events.