Earth… our home planet, a brilliant “blue marble” tirelessly turning through space on an endless journey around the Sun and across the galaxy. Basically a ball of molten rock and metal, its relatively thin crust is mostly covered by a sea of liquid water as well as wrapped in a sea of air… and it’s the complex interaction between all of these things that have allowed life to evolve, thrive, and — so far, anyway — continue to exist on this one particular world.
But how exactly does this work? How, and why, do all of these different factors combine to make a habitable planet? Energy from the Sun, the movement of the atmosphere, the planet’s rotation, the constant churning of ocean currents, the upwelling of materials from deep inside the Earth… all of these play essential roles every day in the survival of nearly every living thing on our planet — including us. To truly understand life on Earth, we must first understand the complex interactions of these forces, and more.
Luckily we have satellites, our “eyes in the sky” that let us look at the entire world on a daily basis and measure and monitor many different processes like never before, letting us see the otherwise invisible big picture of Earth From Space.
An incredible 1,200-mile-wide vortex of spiraling clouds swirling above Saturn’s north pole is seen in all its glory in this stunning image from NASA’s Cassini spacecraft, originally captured last year but recently released by NASA on April 29.
Taking advantage of a new orbital trajectory that puts it high above Saturn’s rings and poles, Cassini acquired the near-infrared images used to make this composite back on Nov. 27, 2012. The resulting image is false color — our eyes aren’t sensitive to those particular wavelengths of light — but still no less amazing!
NASA’s Cassini spacecraft has provided the first direct evidence of small meteoroids breaking into streams of rubble and crashing into Saturn’s rings.
These observations make Saturn’s rings the only location besides Earth, the Moon and Jupiter where meteor impacts have been observed as they occur. The meteoroids at Saturn are estimated to range from about one-half inch to several yards (1 centimeter to several meters) in size.
“These new results imply the current-day impact rates for small particles at Saturn are about the same as those at Earth — two very different neighborhoods in our solar system — and this is exciting to see,” said Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “It took Saturn’s rings acting like a giant meteoroid detector — 100 times the surface area of the Earth — and Cassini’s long-term tour of the Saturn system to address this question.”
Holy Horsehead, Batman! You’ve probably seen photos of the famous Horsehead nebula in Orion many times before, but NOTHING like this!
Astronomers have used NASA’s Hubble Space Telescope to photograph the iconic Horsehead Nebula in a new, infrared light to mark the 23rd anniversary of the famous observatory’s launch aboard the space shuttle Discovery on April 24, 1990.
Looking like an apparition rising from whitecaps of interstellar foam, the iconic Horsehead Nebula has graced astronomy books ever since its discovery more than a century ago. The nebula is a favorite target for amateur and professional astronomers. It is shadowy in optical light. It appears transparent and ethereal when seen at infrared wavelengths. The rich tapestry of the Horsehead Nebula pops out against the backdrop of Milky Way stars and distant galaxies that easily are visible in infrared light.
The nebula is part of the Orion Molecular Cloud, located about 1,500 light-years away in the constellation Orion. It is one of the nearest and most easily-photographed regions in which massive stars are being formed.
According to research by NASA astronomers using the next-generation optics of the 10-meter Keck II telescope, Jupiter’s ice-encrusted moon Europa has hydrogen peroxide (aka H2O2) across much of the surface of its leading hemisphere, a compound that could potentially provide energy for life if it has found its way into the moon’s subsurface ocean.
“Europa has the liquid water and elements, and we think that compounds like peroxide might be an important part of the energy requirement,” said JPL scientist Kevin Hand, the paper’s lead author. “The availability of oxidants like peroxide on Earth was a critical part of the rise of complex, multicellular life.”
There’s nothing like a beautiful sunny day in Gale crater! The rusty sand crunching beneath your wheels, a gentle breeze blowing at a balmy 6º C (43º F), Mount Sharp rising in the distance into a clear blue sky… wait, did I just say blue sky?
Yes I did. But no worries — Mars hasn’t sprouted a nitrogen-and-oxygen atmosphere overnight. The image above is a crop from a panorama made of images from NASA’s Curiosity rover showing Gale crater’s central peak, Mount Sharp (officially Aeolis Mons.) Don’t let the blue sky fool you though — the lighting has been purposely adjusted to look like a sunlit scene on Earth… if only to let geologists more easily refer to their own experience when studying the Martian landscape.
This is a color composite image of Rhea (pronounced REE-ah) I made from raw images acquired by the Cassini spacecraft on March 9, 2013, during its most recent — and final — close pass of the moon. The visible-light colors of Rhea’s frozen surface have been oversaturated to make them more apparent… even so, it’s still a very monochromatic place.