Saturday, November 10, 2018

The Yellow Earth


On October 7, 2018, an astronaut aboard the International Space Station (ISS) shot this photograph while orbiting at an altitude of more than 250 miles over Australia. 

The orange hue enveloping Earth is known as airglow-diffuse bands of light that stretch 50 to 400 miles into our atmosphere. The phenomenon typically occurs when molecules (mostly nitrogen and oxygen) are energized by ultraviolet (UV) radiation from sunlight. To release that energy, atoms in the lower atmosphere bump into each other and lose energy in the collision. The result is colorful airglow.

Airglow reveals some of the workings of the upper reaches of our atmosphere. It can help scientists learn about the movement of particles near the interface of Earth and space, including the connections between space weather and Earth weather. Satellites offer one way to study this dynamic zone. NASA's Ionospheric Connection Explorer (ICON) satellite will help scientists understand the physical processes at work where Earth's atmosphere interacts with near-Earth space.

International Space Station
ICON

Tuesday, November 6, 2018

NGC 1499: The California Nebula

There's even a California in space. Drifting through the Orion Arm of the spiral Milky Way Galaxy, this cosmic cloud by chance echoes the outline ofCalifornia on the west coast of theUnited States. Our own Sun also lies within the Milky Way's Orion Arm, only about 1,500 light-years from theCalifornia Nebula. Also known as NGC 1499, the classic emission nebula is around 100 light-years long. On the featured image, the most prominent glow of the California Nebula is the red light characteristic of hydrogen atoms recombining with long lost electrons, stripped away (ionized) by energetic starlight. The star most likely providing the energetic starlight that ionizes much of the nebular gas is the bright, hot, bluish Xi Persei just to the right of the nebula. A regular target for astrophotographers, the California Nebula can be spotted with a wide-field telescope under a dark sky toward the constellation of Perseus, not far from the Pleiades.

Image Credit & Copyright: Bray Falls

Wednesday, September 19, 2018

Cocoon Nebula Deep Field

Inside the Cocoon Nebula is a newly developing cluster of stars. The cosmic Cocoon on the upper right also punctuates a long trail of obscuringinterstellar dust clouds to its left. Cataloged as IC 5146, the beautiful nebula is nearly 15 light-years wide, located some 3,300 light years away toward the northern constellation of the Swan (Cygnus). Like other star forming regions, it stands out in red, glowing,hydrogen gas excited by young, hot stars and blue, dust-reflected starlight at the edge of a nearly invisible molecular cloud. In fact, the bright star near the center of this nebula is likely only a few hundred thousand years old, powering the nebular glow as it slowly clears outa cavity in the molecular cloud's star forming dust and gas. Thisexceptionally deep color view of the Cocoon Nebula traces tantalizing features within and surrounding the dusty stellar nursery.

Image Credit & Copyright: Marcel Drechsler (Baerenstein Obs.)

First Light Data for NASA's Parker Solar Probe

Just over a month into its mission, NASA's Parker Solar Probe has returned first-light data from each of its four instrument suites. These early observations – while not yet examples of the key science observations Parker Solar Probe will take closer to the Sun – show that each of the instruments is working well. The instruments work in tandem to measure the Sun’s electric and magnetic fields, particles from the Sun and the solar wind, and capture images of the environment around the spacecraft.

This image shows the first-light data from Parker Solar Probe's WISPR (Wide-field Imager for Solar Probe) instrument suite. The right side of this image — from WISPR's inner telescope — has a 40-degree field of view, with its right edge 58.5 degrees from the Sun's center. The bright object slightly to the right of the image's center is Jupiter. The left side of the image is from WISPR’s outer telescope, which has a 58-degree field of view and extends to about 160 degrees from the Sun. It shows the Milky Way, looking at the galactic center. There is a parallax of about 13 degrees in the apparent position of the Sun as viewed from Earth and from Parker Solar Probe.

Image Credit: NASA/Naval Research Laboratory/Parker Solar Probe

Parker Solar Probe

Wednesday, September 12, 2018

Staring Down Hurricane Florence

"Ever stared down the gaping eye of a category 4 hurricane? It's chilling, even from space," says European Space Agency astronaut Alexander Gerst(@Astro_Alex), who is currently living and working aboard the International Space Station as a member of the Expedition 56 crew.

A high-definition video camera outside the space station captured stark and sobering views of Hurricane Florence, a Category 4 storm. The video was taken on Tuesday as Florence churned across the Atlantic in a west-northwesterly direction with winds of 130 miles per hour. The National Hurricane Center forecasts additional strengthening for Florence before it reaches the coastline of North Carolina and South Carolina early Friday, Sept. 14.

Get the latest NASA information on the hurricane.

Image Credit: ESA/NASA–A. Gerst

International Space Station

Tuesday, September 11, 2018

Bright Spots On Ceres

Bright surface features on the dwarf planet Ceres known as faculae were first discovered by NASA'sDawn spacecraft in 2015. This mosaic of one such feature, Cerealia Facula, combines images obtained from altitudes as low as 22 miles (35 km) above Ceres' surface. The mosaic is overlain on a topography model based on images obtained during Dawn's low altitude mapping orbit (240 miles or 385 km altitude). No vertical exaggeration was applied. The center of Cerealia Facula is located at 19.7 degrees north latitude and 239.6 degrees south longitude.

During its mission of over a decade, the Dawn spacecraft has studied the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have formed early in the history of the solar system. The mission's goal is to characterize the early solar system and the processes that dominated its formation.

Image Credit: NASA

Dawn

Friday, September 7, 2018

Aurora around Saturn's North Pole

Are Saturn's auroras like Earth's? To help answer this question, the Hubble Space Telescope and the Cassini spacecraftmonitored Saturn's North Pole simultaneously during Cassini's final orbits around the gas giant in September 2017. During this time,Saturn's tilt caused its North Pole to beclearly visible from Earth. The featured image is a composite of ultraviolet images of aurora and optical images of Saturn's clouds and rings, all taken recently by Hubble. Like on Earth, Saturn's northern auroras can maketotal or partial rings around the pole. Unlike on Earth, however, Saturn's auroras are frequently spirals -- and more likely to peak in brightness just before midnight and dawn. In contrast to Jupiter's aurorasSaturn's aurorasappear better related to connecting Saturn's internal magnetic field to the nearby, variable, solar windSaturn's southern auroras were similarly imaged back in 2004 when the planet's South Pole was clearly visible to Earth.
Image CreditNASAESAHubbleOPAL ProgramJ. DePasquale (STScI), L. Lamy (Obs. Paris)

Hubble Space Telescope