Comet Lovejoy

Named after the amateur astronomer who made the discovery, comet Lovejoy has been making headline news lately. The comet belongs to the Kreutz family of comets, and is most likely a small piece of the Great Comet of 1106 which broke apart in our solar system way back in the 12th century. Comet Lovejoy is on a very eccentric or oval shaped orbit which brings it very close to the sun. It's closest approach to the sun occurred a few days ago, passing only 120,000km (75,000 miles) above the sun's surface, which is extremely close!  Astronomers expected comet Lovejoy to burn up in the sun's atmosphere, but to their surprise Lovejoy survived! The comet's path was captured by both SOHO and SDO, which are satellites monitoring the sun's activity. Below is a video of a compilation of images taken by both satellites. The blue images show the comet approaching the sun towards the bottom left. The yellow images also show the comet approaching the sun, then exiting the sun's atmosphere. The final set of images have an arrow pointing out the comet, which again enters and exists the sun's atmosphere!  The fact that this comet survived means that it's probably much bigger than astronomers predicted; maybe even as larger as 0.5 miles!

Comet, Meteor, or Asteroid?

Leonid Meteor Shower

It's a bird! It's a Plane! It's a comet! No wait, a meteor! Or maybe an Asteroid? I know I'm guilty of using these three word synonymously, but each one has a distinct astronomical definition.

Meteoroids are small bodies that range from the size of a grain of sand to the size of a car. Meteoroids that enter Earth's atmosphere are called meteors and when they fall in groups they are called meteor showers. Most meteors break apart completely as they fall through Earth's atmosphere, but those that survive and impact the ground are called meteorites.

Comets are large bodies in the solar system made mostly of ice, dust and small rocks. They range in size from 100m (~300ft) to 100km (~62 miles) and originate from the outer edges of our solar system. Comets are different from other astronomical bodies because they have a visible tail resulting from the solar wind stripping particles off of the comet. About 4,200 different comets have documented in our solar system, and pass by Earth periodically. Comets continue to orbit the sun until they either break apart from solar radiation, crash into the sun, or get ejected from the solar system.

Asteroids are a broad term for pretty much any body in the solar system that's not a planet, moon, meteoroid, or comet. They can be any size or shape and exist in two main areas: the asteroid belt between Mars and Jupiter and the Kuiper belt beyond the orbit of Neptune. Some asteroids orbit closer the to the planets. Astronomers are working on finding and classifying all such asteroids so we can watch for any that might be on a collision course towards Earth!

Image Credit:  Geek.com/gearlog