Pluto and Its Moon Charon

Postcard DE-4851768 from Germany shows Pluto and its moon Charon.

USPS announces that it will issue the Pluto – Explored! Forever stamps at the Jacob Javits Center in New York City, New York on May 31, 2016 during the World Stamp Show – NY 2016, in order to recognize the NASA's history-making first reconnaissance of Pluto: New Horizons mission in 2015.

The souvenir sheet contains four stamps in two designs. The first design shows an illustration of the New Horizons spacecraft, while the second design shows a striking image of Pluto taken by the spacecraft near its closest approach. The image is a composite of four photos from the Long Range Reconnaissance Imager, combined with data from the sensor Ralph.

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.