All Here… Sorry, Pluto, You Don’t Belong Here

Jupiter in Near-Infrared & Jupiter and Ganymede in Near-UV and Blue

Image credit: Judy Schmidt   @ twitter | instagram

Michael Benson

1. Mimas Above Saturn’s Rings and Shadows, Cassini, November, 7, 2004

2. Mimas Transits Saturn’s Ring Shadows, Cassini, January 18, 2005

Astronauts talking about viewing the earth from the moon, from The Overview Effect: Awe and Self-Transcendent Experience in Space Flight

Beware of the Big, Bad Wolf

Visible within the center of the Crescent nebula is what’s classified as a Wolf-Rayet star. This star is a staggering 250,000 times brighter than the Sun, 15 times more massive, and 3.3 times larger. Its surface temperature is nearly 70,000° C/ 125,000° F. At just 4.7 million years old, it is already toward the end of it’s life and is shedding its outer envelope, ejecting the equivalent of the Sun’s mass every 10,000 years. Within a few hundred thousand years, it is expected to explode as a supernova.   (Image Credit: Michael Miller, Jimmy Walker)

M104: The Sombrero Galaxy.

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Two galaxies on a cosmic collision course.

Image Credit: X-ray: NASA/CXC/SAO/S.Mineo et al, Optical: NASA/STScI, Infr

So it turns out, Pluto is red.

What color is Pluto? If you search for the dwarf planet on Google, images suggest that it’s a sort of steely blue or gray color. But now, NASA’s New Horizons spacecraft is closing in on it, and has learned Mars isn’t the only red planet in our solar system. But the reason it’s red couldn’t be more different from Mars.

Light Echoes from V838 Mon

For reasons unknown, star V838 Mon’s outer surface suddenly greatly expanded with the result that it became the brightest star in the entire Milky Way Galaxy in January 2002. Then, just as suddenly, it faded. A stellar flash like this has never been seen before.

It’s true that supernovae and novae expel matter out into space. But while the V838 Mon flash appears to expel material into space, what is seen here is actually an outwardly moving light echo of the bright flash. In a light echo, light from the flash is reflected by successively more distant rings in the ambient interstellar dust that already surrounded the star.

V838 Mon lies about 20,000 light years away toward the constellation of Monoceros the unicorn. In this Hubble Space Telescope image from February 2004, the light echo is about six light years in diameter.

Image Credit: NASA, APOD, ESA, H. E. Bond (STScI)

Grand Spiral Galaxy  - M 100

Known as a grand design spiral galaxy, M100 is a large galaxy of over 100 billion stars with spiral arms that are like our own Milky Way Galaxy. This Hubble Space Telescope image of M100 was made in 2009 and reveals bright blue star clusters and intricate winding dust lanes which are hallmarks of this class of galaxies. Studies of variable stars in M100 have played an important role in determining the size and age of the Universe.

Credit: NASA/APOD

Comas and Tails of Comets The generally unexpected and sometimes spectacular appearance of comets have triggered the interest of many people throughout history. A bright comet can easily be seen with the naked eye. Comets are usually not discovered until after a coma or tail has formed. Depending on the apparent size of the coma or tail, a comet can be very bright. Some comets have a tail extending more than 45˚ on the sky. The earliest records of comet observations date to ~6000BCE in China. The smaller nucleus (rocky body) of a comet, often only a few kilometres in diameter, is usually hidden from view by the large coma, a cloud of gas and dust roughly 10 to the power of 4-10 to the power of 5 km in diameter and not seen with the naked eye, a large hydrogen coma, between 1 and 10 million km in extent, which surrounds the nucleus and visible gas/dust coma. Two tails are often visible, both in the antisolar direction: a curved yellowish dust tail and a straight ion tail, usually of a blue colour. Comets are usually inert at large heliocentric distances and only develop a coma and tails when they get closer to the sun. When the sublimating gas evolves off the surface of a comet’s nucleus, dust is dragged along. The gas and dust form a comet’s coma and hide the nucleus from view. Most comets are discovered after the coma has formed when they are bright enough to be seen with relatively small telescopes. ~ JM Image Credit More Info: Comets, NASA Coma