on the first day of class my astronomy professor asked us why the night sky was dark. if our universe is infinite, how can there be spaces between the stars? he didn’t answer the question until the last day– because our universe is relatively young, and is still growing. it is finite. not enough stars or galaxies have been formed to fill up the entire night sky.
but what that means to me is that somewhere, in an older universe, the night sky looks like a tapestry of diamonds. somewhere darkness is pale white and glittering. imagine being so surrounded. i haven’t gotten that image out of my head ever since– you could never navigate under such a sky but god it sounds lovely
Like an incredible celestial firework display, dust, ionized material and molecular gas from a dying star form the Helix Nebula. The star is evolving to become a white dwarf star and appears as the tiny blue dot seen at the center. This picture, taken in infrared light by the ESO’s VISTA telescope at the Paranal Observatory, reveals strands of cold nebular gas that is invisible in images taken in visible light. The main ring of the Helix is about two light-years across, roughly half the distance between the Sun and the nearest star. Material from the nebula spreads out from the star to at least four light-years. The Helix Nebula lies in the constellation of Aquarius about 700 light years from Earth. (Credit: ESO)
NASA’s planet-hunting Kepler Telescope has spotted the first roughly Earth-sized world orbiting in the “Goldilocks zone” of another star – offering perhaps the best bet so far for life elsewhere in the universe.
A year on Kepler 452b, which is about 1,400 light years from us in the constellation Cygnus, is 385 days, meaning its orbit is just a bit farther away from its star than the Earth is from the sun. That places it squarely within what planetary scientists call the habitable zone, or “Goldilocks” zone — not too cold and not too hot.
“In my mind, this is the closest planet indeed to Earth,” Jon Jenkins, Kepler data analysis lead at NASA’s Ames Research Center in Moffett Field, Calif, said at a media briefing. “The star is a little bit older and a little bit bigger and brighter, so it’s good that it’s a bit farther from its star.”
Kepler Telescope Introduces Earth To A Very Distant Cousin
Image: Artist’s concept compares Earth (left) to the new planet, called Kepler-452b, which is about 60 percent larger in diameter. Courtesy of NASA/JPL-Caltech/T. Pyle
Billions of years ago, Mars was a very different world. Liquid water flowed in long rivers that emptied into lakes and shallow seas. A thick atmosphere blanketed the planet and kept it warm.
Today, Mars is bitter cold. The Red Planet’s thin and wispy atmosphere provides scant cover for the surface below.
The Mars Atmosphere and Volatile EvolutioN (MAVEN) mission is part of our Mars Scout program. This spacecraft launched in November 2013, and is exploring the Red Planet’s upper atmosphere, ionosphere and interactions with the sun and solar wind.
The purpose of the MAVEN mission is to determine the state of the upper atmosphere of Mars, the processes that control it and the overall atmospheric loss that is currently occurring. Specifically, MAVEN is exploring the processes through which the top of the Martian atmosphere can be lost to space. Scientists think that this loss could be important in explaining the changes in the climate of Mars that have occurred over the last four billion years.
New Findings
Today, Nov. 5, we will share new details of key science findings from our ongoing exploration of Mars during a news briefing at 2 p.m. EDT. This event will be broadcast live on NASA Television. Have questions? Use #askNASA during the briefing.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
The Pinwheel Galaxy - this giant disk of stars, dust and gas is 170,000 light-years across; nearly twice the diameter of the Milky Way. It is estimated to contain at least one trillion stars, approximately 100 billion of which could be like our Sun in terms of temperature and lifetime [6000x4690]
js
The Icy Comet
This image of Comet C/2001 Q4 (NEAT) was taken at the WIYN 0.9-meter telescope at Kitt Peak National Observatory near Tucson, Ariz
Image credit: NASA/ National Science Foundation
Tilt-shift photo of the space shuttle Endeavour by NASA
https://www.nasa.gov/mission_pages/shuttle/flyout/multimedia/endeavour/11-05-16-2.html