Dynamic Astronomy Update - Martin Ratcliffe

These are interesting web links that you should read - it was a busy week in astronomy, with new pictures from Dawn approaching Ceres, and new images of the comet getting very active, from Rosetta. Also new images showing Pluto and its moon Charon orbiting every 6 days.

DAWN APPROACHING CERES

Go here http://dawn.jpl.nasa.gov/ for the latest images of Ceres. Now craters are visible, and the white spots remain unidentified, an intriguing mystery.

Note the next two weeks will see a phenomenal increase in image size and resolution.

This site gives a complete review of the forthcoming weeks.

http://dawnblog.jpl.nasa.gov/2015/01/29/dawn-journal-january-29/

ROSETTA SEES COMET LIGHT UP

The latest images from the Rosetta spacecraft orbiting the comet cataloged as "67P", show the comet nucleus getting active and emitting jets of material - such images have never been seen before, only speculated, and now we see up close what is happening. The jets are largely water ice and dust particles - these form what is known as the "head" of the comet, also known as a "coma" - a large gaseous envelope that surrounds the nucleus. Tenuous wind from the Sun will eventually meet the coma and blow some of the material backwards into a tail.

See latest images here http://blogs.esa.int/rosetta/2015/02/11/new-perspectives-cometwatch-6-february/

Some of the detailed science results are shown here http://blogs.esa.int/rosetta/2015/01/22/getting-to-know-rosettas-comet-science-special-edition/

CLOSING IN ON PLUTO

Third and finally in our roundup of active space missions in this exciting semester, the New Horizons spacecraft has released a small time-lapse sequence of images showing the orbiting moon, Charon, going around Pluto. Currently these images serve as very precise navigation measurements for final tweaking of the spacecraft’s path, if needed. Never before have we had such precise measurements of Pluto's position, from a location 200 million kilometers away (1.2 million miles) - note that Charon doesn't simply orbit Pluto, but both objects orbit around their center of gravity. http://pluto.jhuapl.edu/

Meanwhile:

APOD (Astro Pic Of the Day) posted today a view of the entire solar system viewed from the Voyager spacecraft, taken 25 years ago - this was humanities’ first ever look at its own solar system from outside. The montage of 60 images show all the major planets including Earth. http://apod.nasa.gov/apod/ap150214.html

This spectacular pair of galaxies has begun interacting - as they began to merge each galaxy's gravity drew out streamers of material from the near neighbor, now visible as two streams of stars - such interactions between galaxies occur very slowly, over millions of years. We see this pair as a freeze frame, yet in reality this structure will change as they galaxies continue to merge. An intergalactic pas de deux. http://apod.nasa.gov/apod/ap150212.html

 On February 9 (during our class last week!), the Sun displayed one of the longest filaments of hydrogen gas ever seen. It appears as a dark silhouette against the sun's surface. http://apod.nasa.gov/apod/ap150210.html

Who knows what this week will bring! First we expect a really good image of Ceres from the Dawn spacecraft.