The Hubble Shows How Asteroids and Comets are More Alike than We Realized


Up until recently, scientists have always separated comets and asteroids by one main thing: that comets form gas and dust tails when they get close to the Sun whereas asteroids don’t. But, the more scientists uncover about these two anomalies, the more they’ve discovered it may not be quite so cut and dry.

The tails of comets that we see only appear when volatiles such as water ice is melted by the heat of the Sun. Hence the reason we only see tails on comets and not asteroids is that they are much icier than the other. But, asteroids can also have icy volatiles giving them the appearance of a comet. And vice versa, comets can also have very rocky surfaces making them appear like an asteroid. One such example is that of the asteroid P/2016 J1.  This asteroid was found to have two separate components that had very similar orbits.  Basically what this meant was that once upon a time these two components made up just one asteroid but had someone been broken in two by a collision or gravitational interaction. Simulations have been made that suggest it was around six years ago when this particular asteroid split apart, making it the youngest fragmented asteroid that we’re aware of.

Images from the Hubble Space Telescope of activated asteroid P/2013P5 where the dust tail can be seen. Credit: NASA/ESA.

The P/2016 J1 asteroid is about twice as far from the Sun (at perihelion) than that of Earth and takes about 5.5 years to complete its orbit around the glowing star. Just last year when the asteroid neared perihelion long dusty tails were produced as the two parts of the asteroid came alive, making them look like comets. So, although we may have once classified these two anomalies into dirty snowballs and dry rocks, there are so much more similarities to them that we can now see in them and no longer should we consider them in this way.

Related Links;

More News To Read