Space and astronomy news
Nine months have passed since NASA’s OSIRIS-REx returned its samples of asteroid Bennu to Earth. The samples are some of the Solar System’s primordial, pristine materials. They’ve made their way into scientists’ hands, and their work is uncovering some surprises.
Some of the material in the samples indicates that Bennu had a watery past.
Continue reading “Asteroid Samples Were Once Part of a Wetter World”
After several months of meticulous, careful work, NASA has the final total for their haul of asteroidal material from the OSIRIS-REx mission to Bennu. The highly successful mission successfully collected 121.6 grams, or almost 4.3 ounces, of rock and dust. It won’t be long before scientists get their hands on these samples and start analyzing them.
Continue reading “OSIRIS-REx’s Final Haul: 121.6 Grams from Asteroid Bennu”
NASA’s OSIRIS-REx delivered its precious cargo to Earth on September 24th, 2023. The sample from asteroid Bennu is contained inside the spacecraft’s sampling head, and it’s in safe hands at NASA’s Johnson Space Center in Houston. Two stubborn fasteners delayed the opening of the sampling head, but they’ve been removed, and now we can see inside.
What looks like unremarkable dirt is primordial asteroidal material that’s billions of years old, a natural treasure trove that eager scientists can’t wait to begin studying.
Continue reading “Finally, Let’s Look at the Asteroid Treasure Returned to Earth by OSIRIS-REx”
Carbon and water are so common on Earth that they’re barely worth mentioning. But not if you’re a scientist. They know that carbon and water are life-enabling chemicals and are also links to the larger cosmos.
Initial results from OSIRIS-REx’s Bennu samples show the presence of both in the asteroid’s regolith. Now, eager scientists will begin to piece together how Bennu’s carbon, water, and other molecules fit into the puzzle of the Earth, the Sun, and even the entire Solar System and beyond.
Continue reading “OSIRIS-REx Returned Carbon and Water from Asteroid Bennu”
Most of the spacecraft we send out into the Solar System are never meant to return. Time, space, and entropy overtake them, or else they’re purposely sent crashing to their doom at the end of their missions. But not OSIRIS-REx. Its mission was only a success when it returned to Earth with its rare cargo.
Continue reading “Watch OSIRIS-REx Release its Sample Capsule”
On Sunday, September 23rd, the Sample Retrieval Capsule (SRC) from NASA’s OSIRIS-REx mission landed in the Utah desert. Shortly thereafter, recovery teams arrived in helicopters, inspected and secured the samples, and flew them to the Utah Test and Training Range (UTTR). On Monday, the sample canister was transferred to the Astromaterials Research and Exploration Science Directorate (ARES) in Houston, Texas. Yesterday, on Tuesday, September 26th, NASA announced that the process of unsealing and removing the samples from the canister had begun with the removal of the initial lid.
Continue reading “NASA Opens the Lid on OSIRIS-REx's Sample Capsule”
The OSIRIS-REx spacecraft conducted a two-year reconnaissance and sample collection at the asteroid Bennu, providing crucial data about the 500-meter-wide potentially hazardous rubble pile/space rock. When OSIRIS-REx arrived on Dec. 3, 2018, it needed some tricky navigation and precise maneuvers to make the mission work.
Experts at NASA Goddard’s Scientific Visualization Studio created an amazing visualization of the path the spacecraft took during its investigations. A short film called “A Web Around Asteroid Bennu” highlights the complexity of the mission, and the film is being shown at the SIGGRAPH computer graphics conference in Vancouver, British Columbia, Canada, a festival honoring standout works of computer animated storytelling.
Continue reading “Watch OSIRIS-REx's Complex Orbital Path Around Bennu in This Cool Animation”
Asteroids have been around since early solar system times. However, just because they are ancient bits of history doesn’t mean they don’t change. They collide, they break apart, and now, it turns out their surfaces can erode. That’s due to heat from the Sun. It fractures surface rocks on asteroids and causes what’s called “surface regeneration”. Over time, the cracked and shattered materials can scatter across the surface or even get ejected into space.
How do we know about this erosion? Planetary scientists working on the OSIRIS-REx mission noticed that the surface of asteroid Bennu has rock fractures caused by solar heating. They found that it takes the Sun only about 10,000 to 100,000 years to break up surface rocks on asteroids. This results in a young surface topography on a piece of solar system real estate that’s billions of years old.
Continue reading “The Sun is Eroding Asteroids”
NASA has granted mission extensions to eight different planetary missions, citing the continued excellent operations of the spacecraft, but more importantly, the sustained scientific productivity of these missions, “and the potential to deepen our knowledge and understanding of the solar system and beyond.” Each mission will be extended for three more years.
One of the most exciting extensions gives a new mission to the OSIRIS-REx spacecraft, sending it to one of the most infamous asteroids of them all, the potentially hazardous asteroid Apophis.
Continue reading “Eight Missions are Getting Extensions, Most Exciting: OSIRIS-REx is Going to Asteroid Apophis”
Asteroid Bennu is one of the two most hazardous known asteroids in our Solar System. Luckily, the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer) spacecraft orbited Bennu for more than two years and gathered data that has allowed scientists to better understand the asteroid’s future orbit, trajectory and Earth-impact probability, and even rule out some future impact possibilities.
In the most precise calculations of an asteroid’s trajectory ever made, researchers determined Bennu’s total impact probability through the year 2300 is really small — about 1 in 1,750 (or 0.057%). The team’s paper says the asteroid will make a close approach to Earth in 2135, where Bennu will pose no danger at that time. But Earth’s gravity will alter the asteroid’s path, and the team identifies Sept. 24, 2182 as the most significant single date in terms of a potential impact, with an impact probability of 1 in 2,700 (or about 0.037%).
“The impact probability went up just a little bit, but it’s not a significant change,” said Davide Farnocchia, lead author of the paper, and scientist at the Center for Near Earth Object Studies at NASA’s Jet Propulsion Laboratory, speaking at a press briefing this week. Farnocchia added that means there is a 99.94% probability that Bennu is not on an impact trajectory.
“So, there is no particular reason for concern,” he said. “We have time to keep tracking the asteroid and eventually come to a final answer.”
101955 Bennu was discovered in 1999 by the Lincoln Near-Earth Asteroid Research Team. Since its discovery, Bennu has been extensively tracked with 580 ground-based optical astrometric observations. The asteroid made three relatively close passes of Earth in 1999, 2005, and 2011, during which the Arecibo and Goldstone radar stations collected a wealth of data about Bennu’s motion.
But OSIRIS-REx’s two-year reconnaissance and sample collection has provided crucial data about the 500-meter-wide asteroid, including some surprises. Scientists expected Bennu’s surface to be smooth and sandy, but the first images from OSIRIS-REx revealed a rugged boulder-field, littered with large rocks and loose gravel. The team also expected the asteroid to be geologically quiet, but just six days after arriving in orbit, the spacecraft observed the asteroid ejecting bits of rock, due to rocks on the asteroid cracking because of the day-night heat cycle. We also learned that Bennu has pieces of Vesta on it. The spacecraft also scooped up a sample of rock and dust from the asteroid’s surface in October of 2020, which it will deliver to Earth on Sept. 24, 2023, for further scientific investigation.
But OSIRIS-REx’s precise observations of Bennu’s motions and trajectory allowed for the best estimate yet of the asteroid’s future path.
“The OSIRIS-REx mission has provided exquisitely precise data on Bennu’s position and motion through space to a level never captured before on any asteroid,” said Lindley Johnson, planetary defense officer at NASA’s Planetary Defense Coordination Office at NASA.
The researchers took into account all kinds of small influences, including the tiny gravitational pull of more than 300 other asteroids, and the drag caused by interplanetary dust. They even checked to see if OSIRIS-REx pushed the asteroid off course when the spacecraft briefly touched its rocky surface with its Touch-And-Go (TAG) sample collection maneuver. But that event had a negligible effect, as expected.
The researchers especially focused on a phenomenon called the Yarkovsky effect, where an object in space would, over long periods of time, be noticeably nudged in its orbit by the slight push created when it absorbs sunlight and then re-emits that energy as heat. Over short timeframes, this thrust is minuscule, but over long periods, the effect on the asteroid’s position builds up and can play a significant role in changing an asteroid’s path.
“The Yarkovsky effect will act on all asteroids of all sizes, and while it has been measured for a small fraction of the asteroid population from afar, OSIRIS-REx gave us the first opportunity to measure it in detail as Bennu travelled around the Sun,” said Steve Chesley, senior research scientist at JPL and study co-investigator, in a press release. “The effect on Bennu is equivalent to the weight of three grapes constantly acting on the asteroid – tiny, yes, but significant when determining Bennu’s future impact chances over the decades and centuries to come.”
They also were able to better determine how the asteroid’s orbit will evolve over time and whether it will pass through a “gravitational keyhole” during its 2135 close approach with Earth. These keyholes are areas in space that would set Bennu on a path toward a future impact with Earth if the asteroid were to pass through them at certain times, due to the effect of Earth’s gravitational pull.
The team wrote in their paper that “compared to the information available before the OSIRIS-REx mission, the knowledge of the circumstances of the scattering Earth encounter that will occur in 2135 improves by a factor of 20, thus allowing us to rule out many previously possible impact trajectories.”
“The orbital data from this mission helped us better appreciate Bennu’s impact chances over the next couple of centuries and our overall understanding of potentially hazardous asteroids – an incredible result,” said Dante Lauretta, OSIRIS-REx principal investigator and professor at the University of Arizona. “The spacecraft is now returning home, carrying a precious sample from this fascinating ancient object that will help us better understand not only the history of the solar system but also the role of sunlight in altering Bennu’s orbit since we will measure the asteroid’s thermal properties at unprecedented scales in laboratories on Earth.”
Further reading:
Paper published in Icarus
NASA press release