NASA Astronomy Picture of the Day

June 30, 2024

Earthrise: A Video Reconstruction

About 12 seconds into this video, something unusual happens. The Earth begins to rise. Never seen by humans before, the rise of the Earth over the limb of the Moon occurred about 55.5 years ago and surprised and amazed the crew of Apollo 8. The crew immediately scrambled to take still images of the stunning vista caused by Apollo 8's orbit around the Moon. The featured video is a modern reconstruction of the event as it would have looked were it recorded with a modern movie camera. The colorful orb of our Earth stood out as a familiar icon rising above a distant and unfamiliar moonscape, the whole scene the conceptual reverse of a more familiar moonrise as seen from Earth. To many, the scene also spoke about the unity of humanity: that big blue marble that's us we all live there. The two-minute video is not time-lapse – this is the real speed of the Earth rising through the windows of Apollo 8. Seven months and three missions later, Apollo 11 astronauts would not only circle Earth's moon, but land on it.

https://apod.nasa.gov/apod/astropix.html?

Nasa shares satellite images of world's most remote island Tristan da Cunha

Jun 30, 2024, 15:36 IST

Nasa shared satelite pictures of World's most remote inhabited island Tristan da Cunha. The images were captured by the OLI-2 (Operational Land Imager-2)on Landsat 9 satellite.

Tristan da Cunha, frequently described as the world's most isolated inhabited island, is the youngest and largest among the group situated in the South Atlantic Ocean, roughly equidistant from the southernmost points of South America and Africa.

It is a place where the population of seabirds surpasses that of humans. Queen Mary's Peak, the highest point on Tristan da Cunha, rises up to 2,060 meters (6,760 feet) above sea level.

The peak has steep gullies that extend downward in all directions from its summit.

The island's vegetation is organized into distinct zones that correspond to the height on which it's found. According to the Royal Botanic Gardens, Kew, the coastal fringes of the island were once covered by large tussock-forming grasses, but most of this area has been converted into pasture.

The lower slopes of the volcano are covered by woodlands of Phylica arborea, also known as island cape myrtle (dark green).

As the elevation increases, the vegetation transitions into ecosystems that include tree ferns, sphagnum moss, small grasses, bryophytes, and lichens (light green).

In the waters surrounding the islands, vast underwater forests of giant kelp can be found according to Nasa. The kelp species, "Macrocystis pyrifera," is known for its exceptional growth rate, making it one of the fastest-growing seaweeds globally.

Although suspended sediment may cause discoloration in some parts of the water, indications of kelp forests (visible in green) can be observed in several areas close to the shore.

On the Island's north, Edinburgh of the Seven Seas, a tiny settlement is home to approximately 240 individuals. The primary industries in the area are agriculture and fishing.

A significant number of inhabitants engage in the harvesting of crayfish, which is marketed under the name "Tristan rock lobster." Additionally, they cultivate potatoes and raise farm animals. The island, which is small and round, is a haven for a wide variety of bird

species. In areas far from the town, there are substantial colonies of northern rockhopper penguins, Atlantic yellow-nosed albatross, and broad-billed prion that make their nests on the island.

Tristan da Cunha came into existence approximately 200,000 years ago as a result of volcanic activity along with other islands in the group. In October 1961, the island experienced its most recent eruption, which led to the evacuation of its inhabitants.

Meanwhile, according to radiometric dating techniques, Nightingale Island is the oldest among the three primary islands, with its volcanic rocks dating back between 360,000 and 18 million years.

https://timesofindia.indiatimes.com/home/science/nasa-shares-satellite-images-of-worlds-most-remote-island-tristan-da-cunha/articleshow/111380254.cms

Russian scientists conduct autopsy on 44,000-year-old permafrost wolf carcass

June 28, 20249:17 AM

In Russia's far northeastern Yakutia region, local scientists are performing an autopsy on a wolf frozen in permafrost for around 44,000 years, a find they said was the first of its kind.

Found by chance by locals in Yakutia's Abyyskiy district in 2021, the wolf's body is only now being properly examined by scientists.

"This is the world's first discovery of a late Pleistocene predator," said Albert Protopopov, head of the department for the study of mammoth fauna at the Yakutia Academy of Sciences.

"Its age is about 44,000 years, and there have never been such finds before," he said.

Sandwiched between the Arctic Ocean and in Russia's Arctic far east, Yakutia is a vast region of swamps and forests around the size of Texas, around 95% of which is covered in permafrost.

Winter temperatures in the region have been known to drop to as low as minus 64 degrees Celsius (-83.2°F)

"Usually, it's the herbivorous animals that die, get stuck in swamps, freeze and reach us as a whole. This is the first time when a large carnivore has been found," said Protopopov.

While it's not unusual to find millenia-old animal carcasses buried deep in permafrost, which is slowly melting due to climate change, the wolf is special, Protopopov said.

"It was a very active predator, one of the larger ones. Slightly smaller than cave lions and bears, but a very active, mobile predator, and it was also a scavenger," he added.

For Artyom Nedoluzhko, development director of the paleogenetics laboratory at the European University of St Petersburg, the wolf's remains offer a rare insight into the Yakutia of 44,000 years ago.

"The main goal is to understand what this wolf fed on, who it was, and how it relates to those ancient wolves that inhabited the northeastern part of Eurasia," he said.

https://www.reuters.com/science/russian-scientists-conduct-autopsy-44000-year-old-permafrost-wolf-carcass-2024-06-28/

It's International Asteroid Day, and astronomers have much to celebrate

June 30, 2024

Today, astronomers and space lovers around the world are collectively marveling at our mercurial presence in the universe, particularly as we drift the cosmos amid large asteroids like the one that wiped out the dinosaurs 66 million years ago.

June 30 marks Asteroid Day, a holiday observed annually to reflect on the prospect of a planet-destroying space rock striking Earth and what scientists are doing to mitigate that risk.

The day is observed on the anniversary of the 1908 Tunguska event in Russia, when a space rock about half the size of a football field broke up in the air over a remote forest in Siberia — the biggest asteroid strike ever witnessed on Earth.

With a flash brighter than the sun, followed by a thunder-like noise, the fireball killed herds of reindeer, knocked people who were over 40 miles away (64 kilometers) from the impact off their porches and leveled about 80 million trees.

The impact dumped so much dust in the air that sunsets were fiery red for days, and people who lived as far away as Asia could read newspapers outdoors until midnight.

More recently, in February 2013, a 20-meter (66-foot) space rock struck Earth near the Chelyabinsk city in Russia, injuring about 1,500 people and shattering over 3,000 windows in apartments and commercial buildings.

The shockwave generated by the impact was so strong it circled our planet twice, scientists say.

Although such devastating space rocks land more often in oceans than they do on land, the 2013 asteroid strike, just a decade ago now, "reminded us that these things do happen," Nick Moskovitz of the Lowell Observatory in Arizona told Space.com.

"Asteroids have this strange duality to them in that they probably delivered the ingredients for life to the Earth, but at the same time the wrong impact in the right place could lead to significant damage for whomever may be around."

Asteroid Day is a global awareness campaign spearheaded by the Asteroid Foundation in Luxembourg, and it has been an official day in the United Nations' calendar since December of 2016.

In previous years, the day has been celebrated by dozens of local events in institutions around the world, with talks centering around asteroid science that were topical that year.

Last year, for instance, many events focused on NASA's wildly successful DART mission, which smashed a refrigerator-sized spacecraft into an asteroid named Dimorphos and nudged the space rock off its orbit by 33 minutes, very likely changing the object's shape as well.

DART was humanity's first planetary defense test, and proved scientists had the technology necessary to defend Earth if a similar space rock were to ever be on a collision course with our planet. "Last year, Asteroid Day was very much like DART fest," said Moskovitz. "It's a fun day."

This year's celebration, happening in around 30 institutions worldwide, including those in India, Africa, Europe and Mexico, includes talks about the European Hera mission, which is a follow-up to DART scheduled to launch in October that's designed to assess the aftermath of the mission.

On Friday and Saturday (June 28 and June 29) in Luxembourg, where the Asteroid Foundation is based, events ranged from seminars on asteroid science and space sustainability to workshops where visitors could build spaceships with Legos.

At night, attendees explored the night sky real-time by virtually controlling telescopes in Tuscany, Italy, under the guidance of astronomer Gianluca Masi, who manages the Virtual Telescope Project.

Here's a map outlining locations of similar ongoing events around the world. If none are nearby, you can tune into online discussions about asteroids by astronauts and industry experts that the foundation recently broadcasted.

In the U.S., hundreds of people are expected to join scientists today (June 30) for full-rim tours of the Meteor Crater, where asteroid science demonstrations and themed games have been planned along with food and drinks.

"Right here in northern Arizona, we can see the literal impact of asteroids on our planet," Matt Kent, the president and CEO of Meteor Crater and the Barringer Space Museum, said in a previous announcement. "What better place to hold an Asteroid Day event than here?"

By 7:00 p.m. local time, visitors will begin heading to the Lowell Observatory, which is about a half hour drive away, for telescope viewing and science presentations given by astronomers, including Moskovitz.

Because Asteroid Day falls on a weekend this year, "we could see pretty big crowds between the two sites," he said.

cont.

https://www.space.com/international-asteroid-day-astronomers-celebrate

https://asteroidday.org/news-updates/asteroid-day-festival/

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>CHINESE SPACE TIANLONG-3 ROCKET CRASHES

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