Archives de catégorie : Picture

Lunar Dust and Duct Tape

Why is the Moon so dusty? On Earth, rocks are weathered by wind and water, creating soil and sand. On the Moon, the history of constant micrometeorite bombardment has blasted away at the rocky surface creating a layer of powdery lunar soil or regolith. For the Apollo astronauts and their equipment, the pervasive, fine, gritty dust was definitely a problem. On the lunar surface in December 1972, Apollo 17 astronauts Harrison Schmitt and Eugene Cernan needed to repair one of their rover’s fenders in an effort to keep the rooster tails of dust away from themselves and their gear. This picture reveals the wheel and fender of their dust covered rover along with the ingenious application of spare maps, clamps, and a grey strip of « duct tape ». via NASA https://ift.tt/3urPVhr

Total Lunar Eclipse from Sydney

The reddened shadow of planet Earth plays across the lunar disk in this telescopic image taken on May 26 near Sydney, New South Wales, Australia. On that crisp, clear autumn night a Perigee Full Moon slid through the northern edge of the shadow’s dark central umbra. Short for a lunar eclipse, its total phase lasted only about 14 minutes. The Earth’s shadow was not completely dark though. Instead it was suffused with a faint red light from all the planet’s sunsets and sunrises seen from the perspective of an eclipsed Moon, the reddened sunlight scattered by Earth’s atmosphere. The HDR composite of 6 exposures also shows the wide range of brightness variations within Earth’s umbral shadow against a faint background of stars. via NASA https://ift.tt/34rFgJ3

Mid Eclipse and Milky Way

May’s perigee Full Moon slid through Earth’s shadow yesterday entertaining night skygazers in regions around the Pacific. Seen from western North America, it sinks toward the rugged Sierra Nevada mountain range in this time-lapse series of the total lunar eclipse. Low on the western horizon the Moon was captured at mid-eclipse with two separate exposures. Combined they reveal the eclipsed Moon’s reddened color against the dark night sky and the diffuse starlight band of the Milky Way. Frames taken every five minutes from the fixed camera follow the surrounding progression of the eclipse partial phases. In the foreground a radio telescope dish at California’s Owen’s Valley Radio Observatory points skyward. via NASA https://ift.tt/3fq0q0B

The Outburst Clouds of Star AG Car

What created these unusual clouds? At the center of this 2021 Hubble image sits AG Carinae, a supergiant star located about 20,000 light-years away in the southern constellation Carina. The star’s emitted power is over a million times that of the Sun, making AG Carinae one of the most luminous stars in our Milky Way galaxy. AG Carinae and its neighbor Eta Carinae belong to the scarce Luminous Blue Variable (LBV) class of stars, known for their rare but violent eruptions. The nebula that surrounds AG Car is interpreted as a remnant of one or more such outbursts. This nebula measures 5 light-years across, is estimated to contain about 10 solar masses of gas, and to be at least 10,000 years old. This Hubble image, taken to commemorate Hubble’s 31st launch anniversary, is the first to capture the whole nebula, offering a new perspective on its structure and dust content. The LBVs represent a late and short stage in the lives of some supergiant stars, but explaining their restlessness remains a challenge to humanity’s understanding of how massive stars work. via NASA https://ift.tt/3flAe78

The Moon During a Total Lunar Eclipse

How does the Moon’s appearance change during a total lunar eclipse? The featured time-lapse video was digitally processed to keep the Moon bright and centered during the 5-hour eclipse of 2018 January 31. At first the full moon is visible because only a full moon can undergo a lunar eclipse. Stars move by in the background because the Moon orbits the Earth during the eclipse. The circular shadow of the Earth is then seen moving across the Moon. The light blue hue of the shadow’s edge is related to why Earth’s sky is blue, while the deep red hue of the shadow’s center is related to why the Sun appears red when near the horizon. Tomorrow, people living from southeast Asia, across the Pacific, to the southwest Americas may get to see a Blood Supermoon Total Lunar Eclipse. Here the term blood refers to the (likely) red color of the fully eclipsed Moon, while the term supermoon indicates the Moon’s slightly high angular size — due to being relatively close to the Earth in its slightly elliptical orbit. via NASA https://ift.tt/2Sjoc5j

Lightning Eclipse from the Planet of the Goats

Thunderstorms almost spoiled this view of the spectacular 2011 June 15 total lunar eclipse. Instead, storm clouds parted for 10 minutes during the total eclipse phase and lightning bolts contributed to the dramatic sky. Captured with a 30-second exposure the scene also inspired one of the more memorable titles (thanks to the astrophotographer) in APOD’s now 25-year history. Of course, the lightning reference clearly makes sense, and the shadow play of the dark lunar eclipse was widely viewed across planet Earth in Europe, Africa, Asia, and Australia. The picture itself, however, was shot from the Greek island of Ikaria at Pezi. That area is known as « the planet of the goats » because of the rough terrain and strange looking rocks. The next total lunar eclipse will occur on Wednesday. via NASA https://ift.tt/3vhOHqe

The Galaxy Tree

First came the trees. In the town of Salamanca, Spain, the photographer noticed how distinctive a grove of oak trees looked after being pruned. Next came the galaxy. The photographer stayed up until 2 am, waiting until the Milky Way Galaxy rose above the level of a majestic looking oak. From this carefully chosen perspective, dust lanes in the galaxy appear to be natural continuations to branches of the tree. Last came the light. A flashlight was used on the far side of the tree to project a silhouette. By coincidence, other trees also appeared as similar silhouettes across the relatively bright horizon. The featured image was captured as a single 30-second frame in 2015 and processed to digitally enhance the Milky Way. via NASA https://ift.tt/34bAnUm

Markarian s Chain

Near the heart of the Virgo Galaxy Cluster the string of galaxies known as Markarian’s Chain stretches across this deep telescopic field of view. Anchored in the frame at bottom center by prominent lenticular galaxies, M84 (bottom) and M86, you can follow the chain up and to the right. Near center you’ll spot the pair of interacting galaxies NGC 4438 and NGC 4435, known to some as Markarian’s Eyes. Its center an estimated 50 million light-years distant, the Virgo Cluster itself is the nearest galaxy cluster. With up to about 2,000 member galaxies, it has a noticeable gravitational influence on our own Local Group of Galaxies. Within the Virgo Cluster at least seven galaxies in Markarian’s Chain appear to move coherently, although others may appear to be part of the chain by chance. via NASA https://ift.tt/3bM7zGm

Utopia on Mars

Expansive Utopia Planitia on Mars is strewn with rocks and boulders in this 1976 image. Constructed from the Viking 2 lander’s color and black and white image data, the scene approximates the appearance of the high northern martian plain to the human eye. For scale, the prominent rounded rock near center is about 20 centimeters (just under 8 inches) across. Farther back on the right side of the frame the a dark angular boulder spans about 1.5 meters (5 feet). Also in view are two trenches dug by the lander’s sampler arm, the ejected protective shroud that covered the soil collector head, and one of the lander’s dust covered footpads at the lower right. On May 14, China’s Zhurong Mars rover successfully touchdown on Mars and has returned the first images of` its landing site in Utopia Planitia. via NASA https://ift.tt/2QECGwc

M13: The Great Globular Cluster in Hercules

In 1716, English astronomer Edmond Halley noted, « This is but a little Patch, but it shews itself to the naked Eye, when the Sky is serene and the Moon absent. » Of course, M13 is now less modestly recognized as the Great Globular Cluster in Hercules, one of the brightest globular star clusters in the northern sky. Sharp telescopic views like this one reveal the spectacular cluster’s hundreds of thousands of stars. At a distance of 25,000 light-years, the cluster stars crowd into a region 150 light-years in diameter. Approaching the cluster core upwards of 100 stars could be contained in a cube just 3 light-years on a side. For comparison, the closest star to the Sun is over 4 light-years away. The remarkable range of brightness recorded in this image follows stars into the dense cluster core. Distant background galaxies in the medium-wide field of view include NGC 6207 at the lower right. via NASA https://ift.tt/3owQi9e