What’s Up in the Sky – September, 2014
Close Encounter of the Comet Kind
After having participated in educators’ conferences at the Jet Propulsion Laboratory (through the support of Fennville Public Schools) for the Voyager 2 flybys of Uranus and Neptune, it was with high expectations that I returned to JPL in December of 1999 to witness the touchdown of the Mars Polar Lander on the “Red Planet”. I will never forget the looks on the scientists’ faces as the signal never arrived and it became increasingly clear that the spacecraft had been lost.
Last January, at the European Space Agency’s Mission Operations Center in Germany, scientists were again anxiously awaiting the signal from a spacecraft. This time it was the Rosetta spacecraft, due to wake up after more than two and a half years in deep space hibernation. After waiting 15 minutes one scientist described the mood as “tense factor level 10” and another responded, “it goes to 11”. Finally, after 18 minutes the signal appeared and the room erupted with much cheering and fist pumping. It was back!
Launched in 2004, Rosetta became the first spacecraft to rendezvous with a comet on August 6. For nearly two years it will remain in orbit around the comet (named 67P/Churyumov-Gerasimenko) as it flies past the Sun. It will study the nucleus and its environment and plant a lander on its surface, another first.
The spacecraft is named after the famous Rosetta Stone discovered almost 200 years ago that led to the deciphering of Egyptian hieroglyphics. The lander, Philae, is named for the island in the river Nile where an obelisk was found containing an inscription in two languages that enabled Egyptologists to decipher the Rosetta Stone. Just as these discoveries enabled us to understand ancient Egypt, it is hoped that these spacecraft will give us a better understanding of comets and the early Solar System.
Such a detailed study requires an advanced laboratory and since we can’t bring the comet to the lab, we sent a lab to the comet. In fact, there are two laboratories on this mission: there are 11 instruments on the orbiter and 10 on the lander. They will study the gas and dust surrounding the nucleus. They will take pictures and study spectra. They will work in a wide range of wavelengths including infrared, ultraviolet, microwave, and radio. The lander has instruments that will actually drill into the surface and analyze samples.
It is very tricky to pre-plan a comet mission as things change as it approaches the Sun. We don’t know where and when jets will erupt on the nucleus, or how strong they will be. Nor do we know where on the surface we will find a spot for the lander. So mission control will have its hands full this November when it is scheduled to touch down.
So stay tuned for updates on this mission that will further our understanding of what’s up in the sky.
This month in history:
Sept. 01: Pioneer 11 is first spacecraft to fly past Saturn – 1979
Sept. 03: Last two Apollo Moon landings canceled by NASA – 1970
Sept. 08: Voyager 1 launched – 1977
Sept. 10: Surveyor 5 lands on Moon – 1967
Sept. 21: Galileo mission ends – 2003
Sept. 23: Carolyn Herschel discovers NGC 253 – 1783
Sept. 30: End of daily communication with Pioneer 11 – 1995