Suddenly, Asteroids Everywhere! What’s Going On?

News feeds are once again suddenly populated with astounding stories of asteroids whizzing by, or not. Let’s sort out the fact from the fiction and see whether we have to worry about becoming extinct from a space-borne incident before the UK General Election.

ESA’s asteroids post re: 2011 UL21 and 2024 MK

A lot of the hype can be traced to a post by the European Space Agency from 24th June regarding two asteroids that can be called, albeit unscientifically, ginormous. These two asteroids, 2011 UL21 and 2024 MK, will come closest to Earth on 27th and 29th June, respectively.
In luscious detail, ESA reports on how 2011 UL21 could have been thrown at us by Jupiter, or rather “deflected in our direction” by the Jovian planet. The rock is 2310m across, and is in the largest 1% of all known near-Earth objects. Not to worry, it will pass Earth at more than 17 times the distance between the Earth and the Moon. That’s more than 6 million km away. Still, ESA gleefully notes that it will be visible through telescopes.

The latter asteroid, 2024 MK, is ‘only’ 260m across, but will come closer than the Moon, within 290,000km. ESA Planetary Defense are not concerned about an impact on Earth.

NASA’s asteroids and comets exercise

On 20th June, NASA held a press conference regarding its Planetary Defense Interagency Tabletop Exercise. The exercise itself had been held in April, and was the fifth such test, but the first to include U.S. government partners such as the Federal Emergency Management Agency as well as the first to incorporate data from the DART (Double Asteroid Redirection Test) mission. NASA claimed that no collisions with asteroids and comets are expected at this time, but the agency conducts the test every two years to see how the U.S. response has changed.

What hasn’t changed

Media outlets are churning out headlines regarding the ‘x%’ likelihood of a collision. They are also becoming creative in describing the size of these asteroids. 2011 UL21 in particular is drawing comparisons to mountains as well as hundreds of adult male lions strung end-to-end.