A United Launch Alliance Atlas V rocket with the Lucy spacecraft aboard is seen at Space Launch Complex 41, Thursday, Oct. 14, 2021, at Cape Canaveral Space Force Station in Florida. Credit: NASA/Bill Ingalls.
An early morning launch is planned for the Lucy spacecraft, the first space mission to study Jupiter’s Trojan asteroids. Tomorrow, October 16 at 5:34 a.m. EDT is the first day and time in Lucy’s 21-day launch window, and current weather conditions show a 90% chance of favorable conditions for liftoff from Cape Canaveral Space Force Station in Florida. The launch window remains open for 75 minutes.
Lucy will embark on a 12-year mission to explore the “fossils of planet formation,” Jupiter’s Trojan asteroid swarms. This mission provides the first opportunity to observe these intriguing objects close-up.
This image depicts 42 of the largest objects in the asteroid belt, located between Mars and Jupiter. Most of them are larger than 100 kilometres, with the two biggest asteroids being Ceres and Vesta, which are around 940 and 520 kilometres in diameter, and the two smallest ones being Urania and Ausonia, each only about 90 kilometres. The images of the asteroids have been captured with the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument on ESO’s Very Large Telescope.
A huge team of astronomers have combined forces to use the European Southern Observatory’s Very Large Telescope (ESO’s VLT) to provide the sharpest view ever of 42 of the largest objects in the asteroid belt, located between Mars and Jupiter.
Fittingly, the collection of images was released on the 42nd anniversary of the publication of “The Hitchhiker’s Guide to the Galaxy” by Douglas Adams. In the book, the number 42 is the answer to the “Ultimate Question of Life, the Universe, and Everything.” These 42 images represent some of the sharpest views ever of these objects — which might contribute to answering these ultimate questions!
Plus, there’s a great poster of the asteroids, too:
An artist's impression of a Nearth-Earth Asteroid (NEA) breaking up. Credit: NASA/JPL-Caltech
So far, the battle between life on Earth and asteroids has been completely one-sided. But not for long. Soon, we’ll have the capability to deter asteroids from undesirable encounters with Earth. And while conventional thinking has said that the further away the better when it comes to intercepting one, we can’t assume we’ll always have enough advance warning.
A new study says we might be able to safely destroy potentially dangerous rocky interlopers, even when they get closer to Earth than we’d like.
In astronomy, comets and asteroids are defined very differently. Comets have a “nucleus,” usually made of ice and dust, and a tail when they get near the sun, which is the nucleus material shedding off from the comet itself. Asteroids, on the other hand, are small balls of rock orbiting the sun. Occasionally though, some objects meet the criteria to be both an asteroid and a comet – and a team from the Planetary Science Institute (PSI) think they have found a new one.
Usually, when the topic of asteroid mining comes up, thoughts turn to the riches of the asteroid belt between Mars and Jupiter. The sheer size and scale of the available resources in these asteroids are astounding and overshadow a much more accessible resource – Near-Earth Asteroids (NEAs) that are much closer to home. Now a team from the University of Arizona (UA) has spent some time looking at these near neighbors and realized some are very similar to one of the most famous asteroids in the belt – Psyche.
This is an artist’s depiction of a 10-kilometer (6-mile) diameter asteroid striking the Earth. New evidence in Australia suggests an asteroid 2 to 3 times larger than this struck Earth early in its life. Credit: Don Davis/Southwest Research Institute.
An archeological dig has uncovered evidence of a massive cosmic airburst event approximately 3,600 years ago that destroyed an entire city near the Dead Sea in the Middle East. The event was larger than the famous Tunguska airburst event in Russia in 1908, with a blast 1,000 times more powerful than the Hiroshima atomic bomb. The event flattened the thriving city of Tall el-Hammam, located in what is now Jordan.
Scientists are fortunate enough to have detailed, close-up views of the near-Earth asteroids Bennu and Ryugu. Both asteroids have a diamond shape, for some reason. Why? Up until now, it’s been a puzzle.
Now a team of scientists has tackled the question and may have come up with the answer.
The fastest orbital period asteroid in the Solar System has been discovered at NOIRLab’s CTIO using the powerful 570-megapixel Dark Energy Camera (DECam) in Chile — the Sun’s new nearest neighbor. The illustration shows the locations of the planets and asteroid on the discovery night of 13 August 2021, as they would be seen from a vantage point above the Solar System (north). Credit:
CTIO/NOIRLab/NSF/AURA/J. da Silva (Spaceengine)
Astronomers have spotted the fastest-ever asteroid orbiting Sun — and at times, it gets closer to the Sun than the planet Mercury.
This mosaic image of asteroid Bennu is composed of 12 images collected on Dec. 2, 2018, by the OSIRIS-REx spacecraft's PolyCam instrument from a range of 15 miles (24 kilometers). Credit: NASA/Goddard/University of Arizona
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.
OSIRIS-REx discovered particles being ejected from asteroid Bennu shortly after arriving at the asteroid. Image Credit: NASA/Goddard/University of Arizona/Lockheed Martin
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.”
A diagram showing OSIRIS-REx’s sampling maneuver on October 20th, 2020. Image Credit: NASA/GSFC/UA
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.”
