Category Archives: Asteroids

Want to Help NASA?

NASA: Citizen scientists assemble! NASA’s OSIRIS-REx mission to the asteroid Bennu needs extra pairs of eyes to help choose its sample collection site on the asteroid – and to look for anything else that might be scientifically interesting. 

The OSIRIS-REx spacecraft has been at Bennu since Dec. 3, 2018, mapping the asteroid in detail, while the mission team searches for a sample collection site that is safe, conducive to sample collection and worthy of closer study. One of the biggest challenges of this effort, which the team discovered after arriving at the asteroid five months ago, is that Bennu has an extremely rocky surface and each boulder presents a danger to the spacecraft’s safety. To expedite the sample selection process, the team is asking citizen scientist volunteers to develop a hazard map by counting boulders. 

“For the safety of the spacecraft, the mission team needs a comprehensive catalog of all the boulders near the potential sample collection sites, and I invite members of the public to assist the OSIRIS-REx mission team in accomplishing this essential task,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson.

For this effort, NASA is partnering with CosmoQuest, a project run out of the Planetary Science Institute that supports citizen science initiatives. Volunteers will perform the same tasks that planetary scientists do – measuring Bennu’s boulders and mapping its rocks and craters – through the use of a simple web interface. They will also mark other scientifically interesting features on the asteroid for further investigation.

The boulder mapping work involves a high degree of precision, but it is not difficult. The CosmoQuest mapping app requires a computer with a larger screen and a mouse or trackpad capable of making precise marks. To help volunteers get started, the CosmoQuest team provides an interactive tutorial, as well as additional user assistance through a Discord community and livestreaming sessions on Twitch. 

“We are very pleased and excited to make OSIRIS-REx images available for this important citizen science endeavor,” said Rich Burns, OSIRIS-REx project manager at NASA Goddard Space Flight Center. “Bennu has surprised us with an abundance of boulders. We ask for citizen scientists’ help to evaluate this rugged terrain so that we can keep our spacecraft safe during sample collection operations.”

Sample return isn’t new for NASA – this year, the agency is celebrating the 50th anniversary of the Apollo missions to the Moon, which allowed astronauts to bring back 842 pounds (382 kilograms) of rocks and lunar soil. Those samples helped scientists discover that the Moon has water locked in its rocks and even permanently frozen in craters. These findings and others inspired the agency to create the Artemis program to return humans to the Moon by 2024 and start preparing for human exploration on Mars.

“The OSIRIS-REx mission will continue the Apollo legacy by giving scientists precious samples of an asteroid,” said Lori Glaze, director of the Planetary Science Division at NASA Headquarters in Washington. “These samples will help scientists discover the secrets of planetary formation and the origins of our planet Earth.”

The Bennu mapping campaign continues through July 10, when the mission begins the sample site selection process. Once primary and secondary sites are selected, the spacecraft will begin closer reconnaissance to map the two sites to sub-centimeter resolution. The mission’s Touch-and-Go (TAG) sampling maneuver is scheduled for July 2020, and the spacecraft will return to Earth with its cargo in September 2023.

Goddard provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

To volunteer as a Bennu mapper, visit: Bennu.cosmoquest.org

Gaia’s Asteroid Detections

You go Gaia! A very remarkable mission!

Image: ESA/Gaia/DPAC/CU4, L. Galluccio, F. Mignard, P. Tanga (Observatoire de la Côte d’Azur)

ESA: As it scans the sky surveying stars in the Milky Way galaxy, Gaia has also detected a wealth of asteroids, the small rocky bodies that populate our solar system, mainly between the orbits of Mars and Jupiter. Because they are relatively nearby and orbiting the Sun, asteroids appear to move against the stars in astronomical images, appearing in one snapshot of a given field, but not in images of the same field taken at later times.

Gaia scientists have developed special software to look for these ‘outliers’, matching them with the orbits of known asteroids in order to remove them from the data being used to study stars. But in turn, this information will be used to characterise known asteroids and to discover thousands of new ones.

This image shows Gaia’s detections of asteroids in eight months’ worth of data, compared with the positions on the sky of a sample of 50 000 known asteroids. The colour of the data points is an indication of the accuracy of the detections, showing the separation on the sky between the observed position of Gaia’s detection and the expected position of each asteroid: blue indicates higher accuracy, whereas green and red indicate lower accuracy.

The regions showing lower accuracy of asteroid detections correspond to patches of the sky where the stellar density is very high, thus complicating the identification process.

Bennu’s Southern Region

I really like the perspective of this image.

Bennu is only about 492 meters across and the surface gravity is reportedly in the order of 10 – micro-g (Spaceflight Now) these rocks/boulders really are barely held together.

NASA: This image shows a view across asteroid Bennu’s southern hemisphere and into space, and it demonstrates the number and distribution of boulders across Bennu’s surface. The image was obtained on Mar. 7 by the PolyCam camera on NASA’s OSIRIS-REx spacecraft from a distance of about 3 miles (5 km). The large, light-colored boulder just below the center of the image is about 24 feet (7.4 meters) wide, which is roughly half the width of a basketball court.

Credits: NASA/Goddard/University of Arizona

Bennu Close Up

Here’s a close up of the asteroid Bennu. The image is from NASA’s OSIRIS-REx spacecraft (caption below). You will get a larger version by clicking the image above, however, I encourage you to go to the main image on the NASA page and click that one, it is huge and the detail is amazing. Keep in mind I try to keep the image file size reasonable so people with slower connections don’t have to wait too long and that image is a lot larger in terms of file size – but it’s really good.

NASA: This trio of images acquired by NASA’s OSIRIS-REx spacecraft shows a wide shot and two close-ups of a region in asteroid Bennu’s northern hemisphere. The wide-angle image (left), obtained by the spacecraft’s MapCam camera, shows a 590-foot (180-meter) wide area with many rocks, including some large boulders, and a “pond” of regolith that is mostly devoid of large rocks. The two closer images, obtained by the high-resolution PolyCam camera, show details of areas in the MapCam image, specifically a 50-foot (15 meter) boulder (top) and the regolith pond (bottom). The PolyCam frames are 101 feet (31 meters) across and the boulder depicted is approximately the same size as a humpback whale.

The images were taken on February 25 while the spacecraft was in orbit around Bennu, approximately 1.1 miles (1.8 km) from the asteroid’s surface. The observation plan for this day provided for one MapCam and two PolyCam images every 10 minutes, allowing for this combination of context and detail of Bennu’s surface.

Credit:  NASA/Goddard/University of Arizona

JAXA Probe Lands on Asteroid

Congratulations are in order for the Japanese space agency JAXA! The
Hayabusa 2 Probe has successfully landed on the asteroid
Ryugu’s surface and collected a sample and left the surface.

Here’s the latest status report from JAXA:

National Research and Development Agency Japan Aerospace Exploration Agency (JAXA) executed the asteroid explorer Hayabusa2 operation to touch down the surface of the target asteroid Ryugu for sample retrieval.

Data analysis from Hayabusa2 confirms that the sequence of operation proceeded, including shooting a projectile into the asteroid to collect its sample material. The Hayabusa2 spacecraft is in nominal state. This marks the Hayabusa2 successful touchdown on Ryugu.

Image: JAXA

OSIRIS-REx Sees Home

The NAVCAM aboard the OSIRIS=REx spacecraft took this image on 19 December 2018 and it is looking at Aseroid Bennu and the Earth and Moon. Can you spot them? Click the image for a much larger version and that might help. You can get the full image here – and it’s not so large that even a slow connection will take a long time.

There is also part of a constellation in the lower right, take a guess at that too before reading the caption which is below the fold. I am pleased to say I got it, but only because of dumb-luck, still. . .

Thanks to: NASA, Goddard, University of Arizona, and Lockheed Martin Space for the image.
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Water on Asteroid Bennu?

A new look at asteroid Bennu from the OSIRIS-REx spacecraft courtesy of: NASA, Goddard, and the University of Arizona. If you have not seen it there is a very good animated version of Bennu’s rotation, be warned if you have a slow connection, it is a large file; just be patient it is worth the wait. Video at asteroidmission.org.

The big news, really big news is there may be water in the clays on Bennu:

NASA: Recently analyzed data from NASA’s Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) mission has revealed water locked inside the clays that make up its scientific target, the asteroid Bennu.

During the mission’s approach phase, between mid-August and early December, the spacecraft traveled 1.4 million miles (2.2 million km) on its journey from Earth to arrive at a location 12 miles (19 km) from Bennu on Dec. 3. During this time, the science team on Earth aimed three of the spacecraft’s instruments towards Bennu and began making the mission’s first scientific observations of the asteroid. OSIRIS-REx is NASA’s first asteroid sample return mission.

Data obtained from the spacecraft’s two spectrometers, the OSIRIS-REx Visible and Infrared Spectrometer (OVIRS) and the OSIRIS-REx Thermal Emission Spectrometer (OTES), reveal the presence of molecules that contain oxygen and hydrogen atoms bonded together, known as “hydroxyls.” The team suspects that these hydroxyl groups exist globally across the asteroid in water-bearing clay minerals, meaning that at some point, Bennu’s rocky material interacted with water. While Bennu itself is too small to have ever hosted liquid water, the finding does indicate that liquid water was present at some time on Bennu’s parent body, a much larger asteroid.

“The presence of hydrated minerals across the asteroid confirms that Bennu, a remnant from early in the formation of the solar system, is an excellent specimen for the OSIRIS-REx mission to study the composition of primitive volatiles and organics,” said Amy Simon, OVIRS deputy instrument scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “When samples of this material are returned by the mission to Earth in 2023, scientists will receive a treasure trove of new information about the history and evolution of our solar system.”

Additionally, data obtained from the OSIRIS-REx Camera Suite (OCAMS) corroborate ground-based telescopic observations of Bennu and confirm the original model developed in 2013 by OSIRIS-REx Science Team Chief Michael Nolan and collaborators. That model closely predicted the asteroid’s actual shape, with Bennu’s diameter, rotation rate, inclination, and overall shape presented almost exactly as projected.

One outlier from the predicted shape model is the size of the large boulder near Bennu’s south pole. The ground-based shape model calculated this boulder to be at least 33 feet (10 meters) in height. Preliminary calculations from OCAMS observations show that the boulder is closer to 164 feet (50 meters) in height, with a width of approximately 180 feet (55 meters).

Bennu’s surface material is a mix of very rocky, boulder-filled regions and a few relatively smooth regions that lack boulders. However, the quantity of boulders on the surface is higher than expected. The team will make further observations at closer ranges to more accurately assess where a sample can be taken on Bennu to later be returned to Earth.
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