NASA’s DART Mission: Brace for Impact!!!

Hello, friends!

We are only a few days away from what is, in my opinion, the #1 most important space story of the year.  No, I’m not talking about the launch of Artemis 1.  And no, this has nothing to do with the Webb Telescope either.  I’m talking about NASA’s DART Mission.

For eons now, asteroids have been zipping and zooming past our planet.  Every once in a while, one of those asteroids will hit our planet, causing anywhere from minor to major to global mass extinction event levels of damage.  But on Monday, September 27, 2022, humanity will perform our first ever experiment to see if it’s possible to smack an incoming asteroid away.

The asteroid in question is named Dimorphos.  Dimorphos is not actually a threat to us, but if we’re going to perform an experiment like this, Dimorphos is a rather convenient target for target practice.  That’s because Dimorphos is not just an asteroid; it’s also a moon (or should I call it a moonlet?) orbiting a larger asteroid named Didymos.

When the DART spacecraft crashes into Dimorphos, the force of the impact will change Dimorphos’s orbit around Didymos.  It should be fairly easy for astronomers to measure this change, and thus it should be fairly easy to judge how effective DART was—and just how effective DART would have been against an asteroid that was actually threatening us.

Oh, and just in case anyone’s concerned that DART might accidentally knock Dimorphos out of its original orbit entirely and send it hurtling our way, thus ironically causing the very disaster this mission was meant to help prevent—don’t worry.  Didymos’s gravitational hold on Dimorphos is strong.  No matter what happens on this mission, Didymos is not going to let her little moonlet go (another reason why Dimorphos was selected as the target for this experiment).

So on Monday, September 27, 2022, there will be a head-on collision between an asteroid/moonlet and a NASA spacecraft.

An Italian-built spacecraft named LICIACube will be positioned nearby to observe the experiment.  A multitude of Earth-based telescopes will also be watching.  The European Space Agency also plans to send a follow-up mission (named Hera) in 2026, to check up on Dimorphos after its post-impact orbit has had some time to settle down.

Life on Earth has never been able to defend itself from incoming asteroids before.  Life on Earth has never had the ability to even try, until now [citation needed].  Obviously asteroids are not the only threat to life on our planet.  Obviously this is not the only challenge we need to overcome.  But the DART Mission is a huge first step.  A true giant leap.  No, DART probably won’t get the same kind of love and attention as Webb or Artemis 1, but still I’d say this is the #1 most important space story of the year.  This may be one of the most important science experiments in all of Earth history.

WANT TO LEARN MORE?

P.S.: I said life on Earth has never before had the ability to defend itself from incoming asteroids.  Technically speaking, we cannot be 100% sure that’s true.  Click here to read my post on the Silurian Hypothesis.

Our Place in Space: The DART Mission

Hello, friends!  Welcome to Our Place in Space: A to Z!  For this year’s A to Z Challenge, I’ll be taking you on a partly imaginative and highly optimistic tour of humanity’s future in outer space.  If you don’t know what the A to Z Challenge is, click here to learn more.  In today’s post, D is for…

THE DART MISSION

So far this month, I’ve been telling you about things that I think will happen (or plausibly could happen) at some point in the distant future.  But today, I’m going to talk about something that’ll happen in the not-so-distant future.  Something that will happen in the very near future, actually.  Later this year, in fact!  In late September or early October of 2022, a NASA space probe named DART will deliberately crash into an asteroid named Dimorphos.

Dimorphos is a relatively small asteroid orbiting a much larger asteroid named Didymos.  Basically, Dimorphos is Didymos’s moon.  These two asteroids will be passing fairly close to Earth later this year.  Now I want to be 100% clear about this: neither Didymos nor Dimorphos are going to collide with our planet.  We are in no danger.  But these asteroids will be coming close enough that we could do a little experiment—an experiment to see just how well we could defend our planet from a dangerous, mass-extinction-causing asteroid, should such an asteroid ever come our way.

DART stands for Double Asteroid Redirection Test.  As you can see in the highly technical diagram below, the plan is for the DART spacecraft to have a head-on collision with Dimorphos.

This head-on collision should cause Dimorphos to lose some orbital momentum, which should alter Dimorphos’s orbit around Didymos.  How different will Dimorphos’s new orbit be?  Hard to say.  The exact angle of impact… the astroid’s mineral composition… the amount of debris produced by the collision… all of these things may factor into what Dimorphos’s new orbit looks like.

Astronomers can do all the computer simulations they like, but until we throw a real life projectile at a real life asteroid, we won’t really know what will happen.  Not with any kind of precision.  Ergo, we need to do this experiment.

Looking once more into the distant future, I believe that humanity is going to spread out across space.  Large numbers of people will eventually be living on the Moon and Mars, as well as on other planets and moons of our Solar System.  But I also believe these humans in the distant future will take good care of the Earth.  Among other things, they will know how to defend Earth from incoming asteroids and comets, so that what happened to the dinosaurs never has to happen again.  And that capability—the capability to keep Earth safe from killer asteroids and comets—begins with a little NASA experiment scheduled to occur later this year.

Want to Learn More?

Here are a few papers that I’ve been reading about the upcoming DART Mission.  This is where I got most of the information for today’s post: