Comets vs. Asteroids: Out of This World

Eyewire, citizen science, comet, asteroid, asteroid vs meteor, asteroid vs comet, comet vs meteor, meteor, funny, space rocks

Don’t worry, this isn’t a disaster movie! Starting at 11 AM EST on 1/25 and going for 24 hours, we’ll just be going on a little outer space adventure. Fancy a jaunt on one of these fast-flying puppies? Choose your favorite SSSB (that’s what astronomers call a Small Solar System Body).


  • Ice is nice! Comets are made of rock, dust, frozen water, and various frozen gases like CO2 and methane. When they pass close to the Sun, comets warm up and release some of that dust, water vapor, and gas, forming the coma or tail that gives them their distinct appearance.
  • Meteor showers are usually created by debris from a passing comet, even when you don’t see the comet itself. Earlier this month you might have been lucky enough to catch the Quadrantids shower from the glamorously named comet (196256) 2003 EH1.
  • The next comet you might be able to see with the naked eye is 21P/Giacobini-Zinner, likely visible from late August through September.


  • Asteroids are technically “minor planets,” but this says nothing about their size! The largest asteroids can be around 1000 kilometers in diameter, but they can get all the way down to 1 meter.
  • The biggest asteroid in the asteroid belt, Ceres, was also the first one discovered— by Giuseppe Piazzi in 1801. It’s actually so big that it’s classified as a dwarf planet like Pluto!
  • In Earth’s recorded history, the most significant asteroid collision or near-collision was probably the Tunguska event in 1908, when a meteoroid exploded over Siberia and took out about 80 million trees. Whoa!

The usual bonuses

Earn 5,000 points – 2,500 bonus
Earn 15,000 points – 5,000 bonus
Earn 25,000 points – 10,000 bonus
For every 25,000 points above 25,000 – 5,000 bonus
Member of winning team (if you’ve scored at least 2,500 points) – 10,000 bonus
Highest scorer on each team – 5,000 bonus
Player with #1 overall score – 10,000 bonus
Player with #2 overall score – 5,000 bonus
Player with #3 overall score – 2,500 bonus

For science!

Artwork by Minjeong Kim. This versus was originally suggested by Atani!