Threats from Little Bodies Inside and Outside

Of course the inside threat are those little bodies of coronavirus causing Covid-19. We cover them a lot here. But there are also threats from little bodies outside, way outside. Like asteroids impacting us. And that was the news yesterday when NASA announced improved data from a mission to the asteroid Bennu allowed it to refine its orbital model.

And we have reason to ever just so very slightly worry. Because there is a very slight chance that Bennu will impact Earth. In 2182. The New York Times article where I read the news included a motion graphic produced by NASA to explain that the determining factor will be a near pass in 2135.

Too many keys

Essentially, the exact course Bennu takes as it passes Earth in 2135 will determine its path in 2182. But just a few slight variations could send it colliding into Earth. Though, to be clear, it’s only a 1-in-1750 chance.

NASA used the metaphor of keyholes to explain the concept. The potential orbits in 2135 function as keyholes and should Bennu pass into the right keyhole, it will setup a collision with Earth in 2182. Hence the use of little keyholes in the motion graphic that accompanied the article.

But who knows, if we’re lucky the United Federation of Planets will still be formed in 2161 and the starship Enterprise will gently nudge Bennu back into a non-threatening orbit.

Credit for the piece goes to NASA.

Asteroids on the Moon

I hope everybody enjoyed their holiday. But, before we dive back into the meatier topics of the news, I wanted to share this serpentine graphic from the Guardian I discovered last week. Functionally it is a timeline charting the size of 96 known large asteroid impact craters on the Moon, between 80ºS and 80ºN.

Impacts on the Moon
Impacts on the Moon

The biggest question I have is whether the wrapping layout is necessary. I would prefer a more simplistic and straightforward, well, straight timeline, but I can imagine space constraints forcing the graphic into this box—either for the digital version and/or the likely print version.

The transparencies help to give a sense of density to the strikes, especially in the later years. And the orange ones highlight important or well-known craters like Tycho.

I do wonder, however, if the designer could have added a line at the 290 million years point. Since the graphic’s title calls that year out in particular, it might help the audience more quickly grasp the graphic’s…impact. In theory, the reader can more or less figure it out from the highlighting of the Ohm impact crater that is listed as 291 million years old. But a small grey line like those for the 250 million year increments could have been a nice little touch.

Overall, however, it’s nice to see a compact and helpful space graphic.

Credit for the piece goes to the Guardian graphics team.

Quasi-satellite Asteroid Orbits

Scientists discovered Earth has a new quasi-satellite. It is an asteroid, and it does not orbit the Earth. But, because of the relationship between its orbit and Earth’s around the sun, it is involved in what NASA described as a dance with Earth. This is not Earth’s only dance partner, however, as we interact with a second asteroid as well. The screenshot of a YouTube video (from user britoca) shows how gravity choreographs the second dance.

Cruithne's orbit
Cruithne’s orbit

Credit for the piece goes to YouTube user britoca.