How Big is Rosetta’s Comet?

Pretty darn big, I’d say.

The illustration above shows the relative scale of the comet that ESA’s Rosetta and Philae spacecraft will explore “up-close and personal” later this year. And while it’s one thing to say that the nucleus of Comet 67P/Churyumov-Gerasimenko is about three by five kilometers in diameter, it’s quite another to see it in context with more familiar objects. Think about it — a comet as tall as Mt Fuji!

Artist’s impression (not to scale) of the Rosetta orbiter deploying the Philae lander to comet 67P/Churyumov–Gerasimenko. Credit: ESA–C. Carreau/ATG medialab.

At the time of this writing Rosetta is 35 days out on approach to Comet 67P/C-G, at a distance of about 51,000 km (31,700 miles) and closing. Three “big burn” maneuvers have already been performed between May 7 and June 4 to adjust the spacecraft’s course toward the incoming comet, and after smaller ones on June 18 and July 2 there are a total of five more to go. See details of Rosetta’s burn maneuvers here.

As incredibly sensitive as they are, Rosetta’s instruments — which were able to detect the water vapor coming from Comet 67P/C-G from a distance of over 360,000 km — have even sniffed the hydrazine exhaust from its own thruster burns.

Luckily the remaining burns are relatively small compared to the first three, with the final being very brief, so any data contamination by Rosetta’s own exhaust shouldn’t become an issue once the spacecraft has established orbit in August.

Read more: Rosetta’s Comet Already Sweating the Small Stuff

Launched in March 2004, ESA’s Rosetta mission will be the first to orbit and land a probe on a comet, observing its composition and behavior as it makes its close approach to the Sun in 2015. Click here to see where Rosetta is right now.

Source: ESA’s Rosetta blog

Note: While 3-5 km seems pretty big (especially when stood on end) comet nuclei can be much larger, 10 to 20 km in diameter up to the enormous 40+ km size of Hale-Bopp. As comets go, 67P/C-G is fairly average. (Except that, come August, it will be the only comet with an Earthly spacecraft in tow!)

Jason Major

A graphic designer in Rhode Island, Jason writes about space exploration on his blog Lights In The Dark, Discovery News, and, of course, here on Universe Today. Ad astra!

Recent Posts

Dinkinesh's Moonlet is Only 2-3 Million Years Old

Last November, NASA's Lucy mission conducted a flyby of the asteroid Dinkinish, one of the…

19 hours ago

The Universe Could Be Filled With Ultralight Black Holes That Can't Die

Steven Hawking famously calculated that black holes should evaporate, converting into particles and energy over…

1 day ago

Starlink on Mars? NASA Is Paying SpaceX to Look Into the Idea

NASA has given the go-ahead for SpaceX to work out a plan to adapt its…

2 days ago

Did You Hear Webb Found Life on an Exoplanet? Not so Fast…

The JWST is astronomers' best tool for probing exoplanet atmospheres. Its capable instruments can dissect…

2 days ago

Vera Rubin’s Primary Mirror Gets its First Reflective Coating

First light for the Vera Rubin Observatory (VRO) is quickly approaching and the telescope is…

2 days ago

Two Stars in a Binary System are Very Different. It's Because There Used to be Three

A beautiful nebula in the southern hemisphere with a binary star at it's center seems…

3 days ago