NASA’s Mission to Distract Asteroids-It was the Premise of Multiple Hollywood Movies-But next month, NASA will launch a DART mission aimed at actually doing it.
Mark Hammergren, a local astronomer and planetary scientist, talks about DART and other current NASA missions.
Below is an edited interview with Hammergren.
NASA’s DART mission (DART stands for Double Asteroid Redirection Test) sounds like a Hollywood movie. Please explain what NASA is trying to do here.
Hammer Glen: DART’s mission is to literally go to an asteroid, collide with an asteroid, and change its course a bit. It’s not a big mission. It’s not a big spacecraft, so it doesn’t completely change the orbit of this asteroid, but it does. In particular, I would say that this is a binary asteroid, which is an asteroid with its own moon, and this mission will crash into the asteroid’s moon and slightly divert around its parent asteroid. But in a measurable amount.
For the purposes of this, is this just to show that NASA can actually divert the asteroid, or does it need to?
Hammer Glen: It’s one of the really big symbolic goals. But the scientific goal is, first of all, to measure the asteroid’s response to impact. This is because this technique of crushing spacecraft into asteroids is the best way to divert all kinds of virtual, potentially dangerous asteroids. So by actually testing it and seeing what the asteroid’s reaction is … how much momentum is transferred to the asteroid-all of this is really a kind of unknown. We can model it, but practicing it will be essential before we have to do this if we are on the road.
And this has little effect on the orbit of the asteroid. If you really need to avoid a collision between an asteroid and the Earth, is that enough?
Hammer Glen: Small changes will be added over time. If you change the speed of the asteroid at a low speed, such as a few millimeters per second, it will add up over time. It’s a change in speed. So, just multiply this by the time period and then the lead time until the next impact. All you have to do is miss the Earth thousands of miles to the asteroid. If you have enough time, you can do it with just a few pushes.
NASA will stick to the asteroid and launch a Lucy spacecraft on Jupiter’s Trojan asteroid. What makes this mission so special?
Hammer Glen: The target of the Lucy mission is the trojan Jupiter asteroid. These are Jupiter’s orbit-sharing asteroids, most of which are so-called primitive asteroids that appear to be made of material trapped in deep ice far from the formation of the solar system. Therefore, we believe that they are a repository of the conditions and materials in which the original solar system was formed. By looking at them up close, you should be able to see the evolutionary history of small bodies in the solar system.
The important point is that what we have learned over the last few decades is that the history of the solar system is much more complex than we had previously imagined. And we still have insights into the restructuring and reordering of the solar system, the restructuring of planets, that took place in the very early history of formation. There is a strong reason to believe that giant planets such as Jupiter, Saturn, Uranus, and Neptune all repositioned and continued to reposition early after their ever-evolving formation. And because these giant planets have enormous gravity and pass through these swarms of asteroids and comets, they are all, of course, the history of inferior planets, including Earth, and previously habitable, such as Mars. Venus has a great impact on the planet that could have been.
The mission of Perseverance to Mars is to learn more about the Mars rover exploring the Jezero Crater and its past history. What have we learned?
Hammer Glen: The most important point is that there was definitely a lake. There was certainly a continuous stream of water through the delta to the lake. Looking at a section of the delta, you can connect the history of water flow to the crater. And it’s really fascinating.
Does that ultimately mean that we are in the right place to look for evidence of ancient life?
Hammer Glen: Yes, it is. We don’t know until they actually find something, but it looks like relatively slow and stable water hangs in the lake for a long time, especially in the lower layers of the rocks there. And such gentle sedimentation is where, if not fossil, traces of organic matter are expected to be found.
And this is basically only by studying the geology of the rocks, looking at the sedimentary layers, and finding these random rocks that may have been carried there only by flash flood events. right?
Hammer Glen: absolutely. The rock formations are … literally like the pages of a book. And they are placed in order. Flash floods can then come in and deposit large rocks and large rocks. And by looking at how big those rocks are, and knowing from studies here on Earth, we can understand how big those floods were. How fast the water flowing through the river was. It’s really just geology. This is the old-fashioned normal geology we applied to the Martian setting on Earth. Wonderful.
Note: This story will be updated in the video.
NASA Tests Planet Defense Capabilities on DART Mission | Chicago News
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