If Comet Has a Choice

Comet is in the news as the European Space Agency's spacecraft made a first ever soft landing on a comet after a 10-year, 310-million-mile or 500-million-kilometer journey. However, the mission may have ended early as the spacecraft apparently bounced and landed in a shadow and could not get enough charge to its batteries from solar panels.

A comet is basically a big dirty snow ball that circles the Sun. When getting close to the Sun, it gets heated up and begins to emit gas and particles from its nucleus, forming a visible atmosphere, and sometimes a tail upon the effects of solar radiation and solar wind.

Comets become extinct when they have lost all of their volatile ices and particles as a result of having passed too close to the Sun, or having passed close to the Sun too many times. So, I am wondering if a comet has a choice, will she choose to stay away from the Sun and live as a dirty snow ball eternally, or to get close to the Sun and reveal herself in splendid once and for all?

Postcard US-2107408 to Russia was made from a photo I collected when I was in graduate school. Google Image Search turns up several additional photos at Sunet.SE's ftp site. It looks like to be Comet Hale–Bopp that had its closest approach to Earth on March 22, 1997.

Image Schématique du Soleil

Schematic Image of the Sun and its Environment

This postcard from my space related collection shows the schematic image of the Sun and its environment. It provides a blue print showing the wide range of phenomena studied by the various experiments on board the spacecraft Ulysses.

Ulysses, decommissioned on June 30, 2009, was a joint robotic space probe to study the Sun by NASA and the European Space Agency (ESA). The launch of Ulysses was delayed until October 6, 1990 aboard Discovery (mission STS-41) due to the loss of its initially assigned carrier Challenger. It studied the Sun at all latitudes, breaking the limitation that the Sun had been only observed from low solar latitudes due to the Earth's orbit confined on the ecliptic plane. The mission was managed by JPL.