Archives par étiquette : NASA

Stereo Phobos

Get out your red/blue glasses and float next to Phobos, grooved moon of Mars! Captured in 2004 by the High Resolution Stereo Camera on board ESA’s Mars Express spacecraft, the image data was recorded at a distance of about 200 kilometers from the martian moon. This tantalizing stereo anaglyph view shows the Mars-facing side of Phobos. It highlights the asteroid-like moon’s cratered and grooved surface. Up to hundreds of meters wide, the mysterious grooves may be related to the impact that created Stickney crater, the large crater at the left. Stickney crater is about 10 kilometers across, while Phobos itself is only around 27 kilometers across at its widest point. via NASA https://ift.tt/iB4ecZs

Halo of the Cats Eye

What created the unusual halo around the Cat’s Eye nebula? No one is sure. What is sure is that the Cat’s Eye Nebula (NGC 6543) is one of the best known planetary nebulae on the sky. Although haunting symmetries are seen in the bright central region, this image was taken to feature its intricately structured outer halo, which spans over three light-years across. Planetary nebulae have long been appreciated as a final phase in the life of a Sun-like star. Only recently however, have some planetaries been found to have expansive halos, likely formed from material shrugged off during earlier puzzling episodes in the star’s evolution. While the planetary nebula phase is thought to last for around 10,000 years, astronomers estimate the age of the outer filamentary portions of the Cat’s Eye Nebula’s halo to be 50,000 to 90,000 years. via NASA https://ift.tt/Dsj75hT

A Moon Dressed Like Saturn

Why does Saturn appear so big? It doesn’t — what is pictured are foreground clouds on Earth crossing in front of the Moon. The Moon shows a slight crescent phase with most of its surface visible by reflected Earthlight known as ashen glow. The Sun directly illuminates the brightly lit lunar crescent from the bottom, which means that the Sun must be below the horizon and so the image was taken before sunrise. This double take-inducing picture was captured on 2019 December 24, two days before the Moon slid in front of the Sun to create a solar eclipse. In the foreground, lights from small Guatemalan towns are visible behind the huge volcano Pacaya. via NASA https://ift.tt/17NgzaL

Mountains of Dust in the Carina Nebula

It’s stars versus dust in the Carina Nebula and the stars are winning. More precisely, the energetic light and winds from massive newly formed stars are evaporating and dispersing the dusty stellar nurseries in which they formed. Located in the Carina Nebula and known informally as Mystic Mountain, these pillar’s appearance is dominated by the dark dust even though it is composed mostly of clear hydrogen gas. Dust pillars such as these are actually much thinner than air and only appear as mountains due to relatively small amounts of opaque interstellar dust. About 7,500 light-years distant, the featured image was taken with the Hubble Space Telescope and highlights an interior region of Carina which spans about three light years. Within a few million years, the stars will likely win out completely and the entire dust mountain will evaporate. via NASA https://ift.tt/73lgV9H

Starburst Galaxy M94 from Hubble

Why does this galaxy have a ring of bright blue stars? Beautiful island universe Messier 94 lies a mere 15 million light-years distant in the northern constellation of the Hunting Dogs (Canes Venatici). A popular target for Earth-based astronomers, the face-on spiral galaxy is about 30,000 light-years across, with spiral arms sweeping through the outskirts of its broad disk. But this Hubble Space Telescope field of view spans about 7,000 light-years across M94’s central region. The featured close-up highlights the galaxy’s compact, bright nucleus, prominent inner dust lanes, and the remarkable bluish ring of young massive stars. The ring stars are all likely less than 10 million years old, indicating that M94 is a starburst galaxy that is experiencing an epoch of rapid star formation from inspiraling gas. The circular ripple of blue stars is likely a wave propagating outward, having been triggered by the gravity and rotation of a oval matter distributions. Because M94 is relatively nearby, astronomers can better explore details of its starburst ring. via NASA https://ift.tt/bRtMHJ5

The Eagle Rises

Get out your red/blue glasses and check out this stereo view from lunar orbit. The 3D anaglyph was created from two photographs (AS11-44-6633, AS11-44-6634) taken by astronaut Michael Collins during the 1969 Apollo 11 mission. It features the lunar module ascent stage, dubbed The Eagle, rising to meet the command module in lunar orbit on July 21. Aboard the ascent stage are Neil Armstrong and Buzz Aldrin, the first to walk on the Moon. The smooth, dark area on the lunar surface is Mare Smythii located just below the equator on the extreme eastern edge of the Moon’s near side. Poised beyond the lunar horizon is our fair planet Earth. via NASA https://ift.tt/LONWR6D

SOFIA s Southern Lights

SOFIA, the Stratospheric Observatory for Infrared Astronomy, is a Boeing 747SP aircraft modified to carry a large reflecting telescope into the stratosphere. The ability of the airborne facility to climb above about 99 percent of Earth’s infrared-blocking atmosphere has allowed researchers to observe from almost anywhere over the planet. On a science mission flying deep into the southern auroral oval, astronomer Ian Griffin, director of New Zealand’s Otago Museum, captured this view from the observatory’s south facing starboard side on July 17. Bright star Canopus shines in the southern night above curtains of aurora australis, or southern lights. The plane was flying far south of New Zealand at the time at roughly 62 degrees southern latitude. Unfortunately, after a landing at Christchurch severe weather damaged SOFIA requiring repairs and the cancellation of the remainder of its final southern hemisphere deployment. via NASA https://ift.tt/ouqKI1w

North Celestial Tree

An ancient tree seems to reach out and touch Earth’s North Celestial Pole in this well-planned night skyscape. Consecutive exposures for the timelapse composition were recorded with a camera fixed to a tripod in the Yiwu Desert Poplar Forests in northwest Xinjiang, China. The graceful star trail arcs reflect Earth’s daily rotation around its axis. By extension, the axis of rotation leads to the center of the concentric arcs in the night sky. Known as the North Star, bright star Polaris is a friend to northern hemisphere night sky photographers and celestial navigators alike. That’s because Polaris lies very close to the North Celestial Pole on the sky. Of course it can be found at the tip of an outstretched barren branch in a postcard from a rotating planet. via NASA https://ift.tt/rz8ECsf

Crepuscular Moon Rays over Denmark

This moon made quite an entrance. Typically, a moonrise is quiet and serene. Taking a few minutes to fully peek above the horizon, Earth’s largest orbital companion can remain relatively obscure until it rises high in the nighttime sky. About a week ago, however, and despite being only half lit by the Sun, this rising moon put on a show — at least from this location. The reason was that, as seen from Limfjord in Nykøbing Mors, Denmark, the moon rose below scattered clouds near the horizon. The result, captured here in a single exposure, was that moonlight poured through gaps in the clouds to created what are called crepuscular rays. These rays can fan out dramatically across the sky when starting near the horizon, and can even appear to converge on the other side of the sky. Well behind our Moon, stars from our Milky Way galaxy dot the background, and our galaxy’s largest orbital companion — the Andromeda galaxy — can be found on the upper left. via NASA https://ift.tt/Xal3p9B

Comet NEOWISE Rising over the Adriatic Sea

This sight was worth getting out of bed early. Two years ago this month, Comet C/2020 F3 (NEOWISE) rose before dawn to the delight of northern sky enthusiasts awake that early. Up before sunrise on July 8th, the featured photographer was able to capture in dramatic fashion one of the few comets visible to the unaided eye this century, an inner-Solar System intruder that has become known as the Great Comet of 2020. The resulting video detailed Comet NEOWISE from Italy rising over the Adriatic Sea. The time-lapse video combines over 240 images taken over 30 minutes. The comet was seen rising through a foreground of bright and undulating noctilucent clouds, and before a background of distant stars. Comet NEOWISE remained unexpectedly bright until 2020 August, with its ion and dust tails found to emanate from a nucleus spanning about five kilometers across. via NASA https://ift.tt/tF1vP0x