The Only Home We’ve Ever Known. Clouds And Sunlight Over The Indian Ocean, As Seen From Discovery During

What Happened to Mars?

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.

Our MAVEN Mission

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 

Black holes

             Perseus Black hole                

                   Black holes are objects that have collapsed under their own weight to a point, creating an object that is very small but enormously dense. It is a region of space that has a gravitational pull so strong that no imminent particle or electromagnetic radiation can escape from it. This astonishing concept of black hole was first given by John Michell in 1783.He proposed that if you take the sun and compress it to a very small volume it would have a gravitational pull so strong that you have to travel at speeds greater than the speed of light to escape it.At first black holes are thought to be theoretical concepts which do not exist. But later they turned out to be very real. So how do these giant suckers form?

                 In order to understand the formation of a black hole we need to understand the formation and the life cycle of stars. A star is formed when large amounts of dust and gases, mainly hydrogen gas condense and collapse under its own gravitational force. As the gas collapses, the atoms of the gas collide with each other at higher and higher speeds resulting in the heating of the gas. Ultimately the gas becomes so hot that when the hydrogen atoms collide they don’t bounce off, but fuse together to form helium atoms, same as in the hydrogen bomb. As a result a large amount of heat is released which is the reason why stars shine. This heat increases the pressure of the gas until it balances out the gravitational pull and the gas stops contracting. Hence a star is formed.

     The stars are usually stable as long as they have hydrogen in them. As the hydrogen runs out, the fusion reaction stops. To keep the fusion reaction going the star turns to its helium reserve. After it runs out of helium, it switches to carbon, and then oxygen. Stars with the mass of our Sun stop at this point as they don’t have enough energy to continue the fusion process and become white dwarfs. But stars with about 5 times the mass of our sun continue further to produce silicon, aluminum, potassium so on up to iron. No further energy can be produced by fusing iron atoms so the star starts to cool down. Once the external force of radiation stops acting the gravitational pull takes over and the star begins to contract. The entire mass of the star collapses into smaller and smaller volume of space. Eventually when the star has contracted to a certain critical radius, the gravitational field at the surface becomes so strong that even light cannot escape it. And this is how a black hole is formed.

     Another way of formation of black hole is when two neutron stars collide with each other. When they collide their combined mass results in a very high gravitational force that leads to a collapse and a black hole is formed.

In this image, information from the Chandra X-ray Observatory is combined with images from the Hubble Space Telescope. NASA believes these two black holes are spiraling toward each other and have been doing so for 30 years.

Spectacular!

Credit: Fragile Oasis

Auroras Colorful Veil Over Earth : NASA astronaut Scott Kelly shared this photograph on social media, taken from the International Space Station on August 15, 2015. Kelly wrote, #Aurora trailing a colorful veil over Earth this morning. Good morning from @space_station! #YearInSpace

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The Bubble Nebula (NGC 7635) Image Credit: NASA/ESA

This photograph of Neptune was reconstructed from two images taken by Voyager 2’s narrow-angle camera, through the green and clear filters. At the north (top) is the Great Dark Spot, accompanied by bright, white clouds that undergo rapid changes in appearance.

Credit: NASA

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December 2006: Constructing the Space Station : NASA astronaut Robert Curbeam works on the International Space Station’s S1 truss during the space shuttle Discovery’s STS-116 mission in Dec. 2006. (via NASA)

This Distant World May Be The First Ringed Planet Discovered Outside Our Solar System

Planet J1407b is 430 light years from Earth and 10-40 times the size of Jupiter. It’s too soon to tell if these truly are rings, but if they are…

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Remember kids: Pluto is not a planet, WAS never a planet, and any acknowledgement of Pluto as a planet was an error of assumption