October 14, 2014 8:05 pm

A Tale of Two Comets – Siding Spring and 67P

In the next few weeks, two comets are going to become centers of attention here on Earth.

First up, on October 19^th, Comet Siding Spring will brush past Mars at a range of 87,000 miles, which is about a third of the distance between the Earth and the moon.

According to NASA, “Siding Spring’s nucleus will come closest to Mars around 11:27 a.m. PDT (2:27 p.m. EDT), hurtling at about 126,000 mph (56 kilometers per second). This proximity will provide an unprecedented opportunity for researchers to gather data on both the comet and its effect on the Martian atmosphere…”

In fact, NASA says this is Siding Spring’s first journey into the inner solar system, and it is also the first comet from the Oort Cloud that has ever been studied up close by a spacecraft from Earth.

NASA is not wasting a single trick… while still taking precautions. They’ve repositioned the Mars Odyssey orbiter, the Mars Reconnaissance Orbiter, and MAVEN for safety to reduce the impact risk from comet-related debris like dust particles. The Curiosity and Opportunity rovers will also observe the comet from the surface, where NASA says they’ll be protected from any dust by Mars’ atmosphere.

And that’s not all: the Hubble Space Telescope, Kepler, Swift, Spitzer, Chandra, NEOWISE, STEREO and SOHO will also image the comet.

You can get images, videos, animations and much more detail here on the NASA website.

Next up, the European Space Agency’s Rosetta spacecraft will be deploying its Philae lander to the surface of Comet 67P/Churyumov-Gerasimenko on Nov. 12^th. This will be humanity’s first attempt at a soft-landing on a comet. (Does anybody else have scenes from the movies Armageddon or Deep Impact flashing into their brains at the moment?)

Rosetta has studying Comet 67P since its arrival there on August 6 after a 10-year long journey. It is the first spacecraft in history to ever rendezvous with a comet, but in just under a month, if things go well, all attention will shift from Rosetta to the 100kg Philae lander which will touch down on a landing site designated as Site J on the comet’s smaller “lobe.”

We’ll be posting more about Rosetta and Philae as the 12^th gets closer, but for now, if you want to learn more or watch a video, click here.

Oh, and if those two comets aren’t enough, don’t forget that there’s a partial Solar eclipse visible in North America on October 23^rd. EarthSky has a good article on the solar eclipse including safety instructions here.

That’s it for now. Keep Looking Up!

–Jeffrey Simons