New findings from researchers at @NASA and other international teams has discovered a link between the bombardment history of our moon and that of the asteroid Vesta. It appears that the same set of projectiles that hit our moon – and presumably other objects in the inner Solar System – 4 billion years ago also impacted Vesta.
Vesta is an asteroid in our Solar System’s main asteroid belt, between the orbits of Jupiter and Mars. Researchers studying this asteroid have compared moon rocks brought back from the Apollo missions to the findings on Vesta and determined that the same set of projectiles were responsible for both sets of bombardments. And they point to a 4-billion year old disruption of the Solar System:
The findings support the theory that the repositioning of gas giant planets like Jupiter and Saturn from their original orbits to their current location destabilized portions of the asteroid belt and triggered a solar system-wide bombardment of asteroids billions of years ago, called the lunar cataclysm.
The research provides new constraints on the start and duration of the lunar cataclysm, and demonstrates that the cataclysm was an event that affected not only the inner solar system planets, but the asteroid belt as well.
No one is saying that, exactly. Even if there were a liquid, it wouldn’t be water, as the asteroid is far to distant from the sun and much too cold for liquid water.
But scientists are puzzling over the observations of Jennifer Scully, a University of California scientist who is working on the Vesta project. She has seen gullies and what seem to be flows down craters on the surface of the asteroid that so far have defied explanation.
On Earth, the answer would be simple: the gullies are created by liquid water flows eroding the surrounding landscape. On Mars, similar featured have been observed and attributed to liquid water in the Red Planet’s distant past.
But similar shapes on Vesta can have no such explanations, which means that if other erosive forces are at play, then even agreed-upon answers for Mars may be in question:
Indeed, scientists have suggested various explanations for gullies on Mars since fresh-looking gullies were discovered in images from NASA’s Mars Global Surveyor in 2000. Some of the proposed Martian mechanisms involve water, some carbon dioxide, and some neither. One study in 2010 suggested that carbon-dioxide frost was causing fresh flows of sand on the Red Planet.
This is one more reason that scientific data is always important and often surprising: study of two completely different systems may reveal new facts that change our understanding of both systems. It isn’t rare, in fact, it is what science is all about.
Interested? Check out our archives on Vesta and NASA for even more great stuff!
As my attention is turned more and more to NASA’s Jet Propulsion Laboratory, I have to admit that I’m getting confused with all the various missions. Now that I’m starting to get regular press releases from JPL, they’re all starting to run together. After only last year bemoaning the loss of the Space Shuttle program, it is shocking to discover just how much is really going on in space!
So, while the JPL website lists all its programs in alphabetical order, I thought I’d take the time to list out the more news-making missions here:
Miss the sunrise this morning? No worries. @NASAJPL (the Jet Propulsion Labs at NASA) gives you a virtual fly-over of the asteroid Vesta, composited from the many topographical photos taken by the Dawn mission. The video below shows the craters, mountains and other features of this 330 mile wide satellite that orbits our sun in the asteroid belt.
And Vesta is big: it comprises an estimated 9% of the total mass of the asteroid belt – which is the ring of asteroids and debris that orbits between Mars and Jupiter. It is considered the most geologically-diverse of the asteroids studied so far, containing huge features including a crater 285 miles across – nearly the whole diameter! – that is evidence of an impact with another object.
In fact, Vesta just behind to the dwarf planet Ceres in size, making it nearly big enough to sit in the same pantheon of semi-planets as the former planet Pluto.