NASA Astronomy Picture of the Day

May 29, 2024

Stairway to the Milky Way

What happens if you ascend this stairway to the Milky Way? Before answering that, let's understand the beautiful sky you will see. Most eye-catching is the grand arch of the Milky Way Galaxy, the band that is the central disk of our galaxy which is straight but distorted by the wide-angle nature of this composite image. Many stars well in front of the Milk Way will be visible, with the bright white star just below the stellar arch being Altair, and the bright blue star above it being Vega. The air glows green on the left, just above the yellow cloud deck. The featured image was taken last month on Portugal's Madeira Island in the North Atlantic Ocean. Oh, and what happens after you reach the top of these stairs and admire the amazing sky is, quite probably, that you then descend down the stairs on the other side.

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

Discovery Alert: Spock’s Home Planet Goes ‘Poof’

MAY 28, 2024

The discovery

A planet thought to orbit the star 40 Eridani A – host to Mr. Spock’s fictional home planet, Vulcan, in the “Star Trek” universe – is really a kind of astronomical illusion caused by the pulses and jitters of the star itself, a new study shows.

Key facts

The possible detection of a planet orbiting a star that Star Trek made famous drew excitement and plenty of attention when it was announced in 2018. Only five years later, the planet appeared to be on shaky ground when other researchers questioned whether it was there at all. Now, precision measurements using a NASA-NSF instrument, installed a few years ago atop Kitt Peak in Arizona, seem to have returned the planet Vulcan even more definitively to the realm of science fiction.

Details

Two methods for detecting exoplanets – planets orbiting other stars – dominate all others in the continuing search for strange new worlds. The transit method, watching for the tiny dip in starlight as a planet crosses the face of its star, is responsible for the vast majority of detections. But the “radial velocity” method also has racked up a healthy share of exoplanet discoveries. This method is especially important for systems with planets that don’t, from Earth’s point of view, cross the faces of their stars. By tracking subtle shifts in starlight, scientists can measure “wobbles” in the star itself, as the gravity of an orbiting planet tugs it one way, then another. For very large planets, the radial velocity signal mostly leads to unambiguous planet detections. But not-so-large planets can be problematic.

Even the scientists who made the original, possible detection of planet HD 26965 b – almost immediately compared to the fictional Vulcan – cautioned that it could turn out to be messy stellar jitters masquerading as a planet. They reported evidence of a “super-Earth” – larger than Earth, smaller than Neptune – in a 42-day orbit around a Sun-like star about 16 light-years away. The new analysis, using high-precision radial velocity measurements not yet available in 2018, confirms that caution about the possible discovery was justified.

The bad news for Star Trek fans comes from an instrument known as NEID, a recent addition to the complex of telescopes at Kitt Peak National Observatory. NEID, like other radial velocity instruments, relies on the “Doppler” effect: shifts in the light spectrum of a star that reveal its wobbling motions. In this case, parsing out the supposed planet signal at various wavelengths of light, emitted from different levels of the star’s outer shell, or photosphere, revealed significant differences between individual wavelength measurements – their Doppler shifts – and the total signal when they were all combined. That means, in all likelihood, the planet signal is really the flickering of something on the star’s surface that coincides with a 42-day rotation – perhaps the roiling of hotter and cooler layers beneath the star’s surface, called convection, combined with stellar surface features such as spots and “plages,” which are bright, active regions. Both can alter a star’s radial velocity signals.

While the new finding, at least for now, robs star 40 Eridani A of its possible planet Vulcan, the news isn’t all bad. The demonstration of such finely tuned radial velocity measurements holds out the promise of making sharper observational distinctions between actual planets and the shakes and rattles on surfaces of distant stars.

Fun facts

Even the destruction of Vulcan has been anticipated in the Star Trek universe. Vulcan was first identified as Spock’s home planet in the original 1960s television series. But in the 2009 film, “Star Trek,” a Romulan villain named Nero employs an artificial black hole to blow Spock’s home world out of existence.

The discoverers

A science team led by astronomer Abigail Burrows of Dartmouth College, and previously of NASA’s Jet Propulsion Laboratory, published a paper describing the new result, “The death of Vulcan: NEID reveals the planet candidate orbiting HD 26965 is stellar activity,” in The Astronomical Journal in May 2024 (Note: HD 26965 is an alternate designation for the star, 40 Eridani A.)

https://science.nasa.gov/universe/exoplanets/discovery-alert-spocks-home-planet-goes-poof/

Ongoing Venus Volcanic Activity Discovered With NASA’s Magellan Data

MAY 27, 2024

Direct geological evidence of recent volcanic activity on Venus has been observed for a second time.

Scientists in Italy analyzed archival data from NASA’s Magellan mission to reveal surface changes indicating the formation of new rock from lava flows linked to volcanoes that erupted while the spacecraft orbited the planet. Managed by NASA’s Jet Propulsion Laboratory in Southern California, Magellan mapped 98% of the planet’s surface from 1990 to 1992, and the images it generated remain the most detailed of Venus to date.

“Using these maps as a guide, our results show that Venus may be far more volcanically active than previously thought,” said Davide Sulcanese of d’Annunzio University in Pescara, Italy, who led the study.

“By analyzing the lava flows we observed in two locations on the planet, we have discovered that the volcanic activity on Venus could be comparable to that on Earth.”

This latest discovery builds on the historic 2023 discovery of images from Magellan’s synthetic aperture radar that revealed changes to a vent associated with the volcano Maat Mons near Venus’ equator.

The radar images proved to be the first direct evidence of a recent volcanic eruption on the planet.

By comparing Magellan radar images over time, the authors of the 2023 study spotted changes caused by the outflow of molten rock from Venus’ subsurface filling the vent’s crater and spilling down the vent’s slopes.

Scientists study active volcanoes to understand how a planet’s interior can shape its crust, drive its evolution, and affect its habitability. The discovery of recent volcanism on Venus provides a valuable insight to the planet’s history and why it took a different evolutionary path than Earth.

For the new study, published in the journal Nature Astronomy, the researchers likewise focused on archival data from Magellan’s synthetic aperture radar.

Radio waves sent by the radar traveled through Venus’ thick cloud cover, then bounced off the planet’s surface and back to the spacecraft.

Called backscatter, these reflected radar signals carried information about the rocky surface material they encountered.

The two locations studied were the volcano Sif Mons in Eistla Regio and the western part of Niobe Planitia, which is home to numerous volcanic features.

By analyzing the backscatter data received from both locations in 1990 and again in 1992, the researchers found that radar signal strength increased along certain paths during the later orbits. These changes suggested the formation of new rock, most likely solidified lava from volcanic activity that occurred during that two-year period. But they also considered other possibilities, such as the presence of micro-dunes (formed from windblown sand) and atmospheric effects that could interfere with the radar signal.

To help confirm new rock, the researchers analyzed Magellan’s altimetry (surface height) data to determine slope of the topography and locate obstacles that lava would flow around.

“We interpret these signals as flows along slopes or volcanic plains that can deviate around obstacles such as shield volcanoes like a fluid,” said study co-author Marco Mastrogiuseppe of Sapienza University of Rome.

“After ruling out other possibilities, we confirmed our best interpretation is that these are new lava flows.”

Using flows on Earth as a comparison, the researchers estimate new rock that was emplaced in both locations to be between 10 and 66 feet (3 and 20 meters) deep, on average. They also estimate that the Sif Mons eruption produced about 12 square miles (30 square kilometers) of rock — enough to fill at least 36,000 Olympic-size swimming pools. The Niobe Planitia eruption produced about 17 square miles (45 square kilometers) of rock, which would fill 54,000 Olympic swimming pools.

As a comparison, the 2022 eruption of Mauna Loa in Hawaii, Earth’s largest active volcano, produced a lava flow with enough material to fill 100,000 Olympic pools.

“This exciting work provides another example of volcanic change on Venus from new lava flows that augments the vent change Dr. Robert Herrick and I reported last year,” said Scott Hensley, senior research scientist at JPL and co-author of the 2023 study. “This result, in tandem with the earlier discovery of present-day geologic activity, increases the excitement in the planetary science community for future missions to Venus.”

cont.

https://www.nasa.gov/centers-and-facilities/jpl/ongoing-venus-volcanic-activity-discovered-with-nasas-magellan-data/

NASA to Provide Coverage of Progress 88 Launch, Space Station Docking

MAY 28, 2024

NASA will provide live launch and docking coverage of a Roscosmos cargo spacecraft carrying about three tons of food, fuel, and supplies for the Expedition 71 crew aboard the International Space Station.

The unpiloted Progress 88 spacecraft is scheduled to launch at 5:43 a.m. EDT (2:43 p.m. Baikonur time) Thursday, May 30, on a Soyuz rocket from the Baikonur Cosmodrome in Kazakhstan.

Live launch coverage will begin at 5:15 a.m. on NASA+, NASA Television, the NASA app, YouTube, and the agency’s website. Learn how to stream NASA TV through a variety of platforms including social media.

After a two-day in-orbit journey to the station, the spacecraft will automatically dock to the space-facing port of orbiting laboratory’s Poisk module at 7:47 a.m., Saturday, June 1. NASA coverage of rendezvous and docking will begin at 7 a.m. on NASA+, NASA Television, the NASA app, YouTube, and the agency’s website.

The spacecraft will remain docked at the station for almost six months before departing in late November for a re-entry into Earth’s atmosphere to dispose of trash loaded by the crew.

The International Space Station is a convergence of science, technology, and human innovation that enables research not possible on Earth. For more than 23 years, NASA has supported a continuous U.S. human presence aboard the orbiting laboratory, through which astronauts have learned to live and work in space for extended periods of time. The space station is a springboard for the development of a low Earth economy and NASA’s next great leaps in exploration, including missions to the Moon under Artemis and ultimately, human exploration of Mars.

https://www.nasa.gov/news-release/nasa-to-provide-coverage-of-progress-88-launch-space-station-docking/

Just keep swimming! Zebrafish doing fine in zero gravity on China's Tiangong space station

May 28, 2024

The four zebrafish China sent to its space station are thriving after spending almost a month in orbit.

Launched on April 25 alongside three astronauts aboard the Shenzhou-18 spacecraft, the zebrafish and four grams of goldfish algae are currently in good condition in their aquatic habitat on China's Tiangong space station, the Xinhua News Agency reported.

The so-called "aquastronauts" are part of a research project led by the Chinese Academy of Sciences (CAS) to study the impact microgravity and a confined ecosystem has on the growth, development and behavior of vertebrates.

The research — the country's first in-orbit aquatic ecological research project — relied on establishing a self-sustaining aquatic ecosystem in orbit.

China's Tiangong space station orbits Earth at an altitude between 217 and 280 miles (340 to 450 kilometers), which is approximately the same orbital height as the International Space Station (ISS). Astronauts (or taikonauts, as China's spaceflyers are called) studying the zebrafish have successfully collected water samples twice and replaced the fish food box once. This initiative marks the first vertebrate-raising experiment of its kind in space, according to Xinhua.

The zebrafish, a small fish species belonging to the minnow family, are one of the most frequently used model organisms for genetic and developmental studies.

The research currently underway on Tiangong will explore the effects of microgravity and radiation on biological systems and aid in mitigating bone loss in astronauts.

Given the microgravity environment on Tiangong, the astronauts have also observed the zebrafish exhibiting unusual directional behavior, such as inverted swimming and rotary movements, Zheng Weibo, a researcher at Shanghai Institute of Technical Physics of the CAS, shared at a public science day event in Beijing on May 19.

"Zebrafish, as a model animal with genetic similarity to humans, can be used for research on many human diseases," Wang Gaohong, a researcher at the Institute of Hydrobiology of the CAS, said in the report from Xinhua.

Some 70% of human genes have an analogue in the zebrafish genome, according to the National Institutes of Health.

In addition to water samples, the astronauts will collect fish egg samples for their research.

Zebrafish serve as a unique biological model because their embryos are transparent and develop outside of the uterus, meaning the fish’s development can be studied starting from fertilization.

What's more is the self-sustaining aquatic ecosystem, where the algae and fish sustain each other, also has implications for understanding the challenges of maintaining life support systems for long-duration space missions and future space habitats.

https://www.space.com/china-tiangong-space-station-zebrafish-healthy

>>20932946

Notable with sauce

>>20932988

Chekt, thanks.

Found it.

https://brevardfl.granicus.com/player/clip/448?view_id=1&redirect=true

Verizon plots $100 million direct-to-smartphone satellite investment

May 29, 2024

Verizon plans to invest $100 million in AST SpaceMobile after joining its cellular rival AT&T to partner with the direct-to-smartphone satellite operator.

AST SpaceMobile founder, chair and CEO Abel Avellan hailed the deal as a “transformational commercial milestone” for the venture’s proposed constellation, paving the way to fully cover the continental United States with radio waves both telcos have in the 850 megahertz band.

Srini Kalapala, Verizon’s senior vice president of technology and product development, said the telco plans to use AST SpaceMobile’s satellites to provide “essential connectivity in remote corners of the U.S,” where its cellular signals do not reach customers via traditional land-based infrastructure.

The $100 million commitment comprises $65 million ​in commercial prepayments and $35 million in debt that pays interest to Verizon but could later be converted into AST SpaceMobile shares.

AST SpaceMobile chief strategy officer Scott Wisniewski said $45 million of the prepayment commitment is tied to conditions that include regulatory approvals and entry into a definitive commercial agreement.

“This is the beginning of what we see as a long relationship with Verizon,” Wisniewski told SpaceNews via email.

In January, AT&T agreed to make a $20 million prepayment tied to the successful operations of the first five commercial BlueBird satellites AST SpaceMobile is building in-house, collectively known as Block 1.

AT&T, Google and British telco Vodafone have also banded together to provide $110 million in funding to AST SpaceMobile via convertible debt.

The Texas-based satellite venture says it has agreements with over 45 mobile network operators worldwide, serving more than 2.8 billion subscribers.

Evolving partnerships

AT&T has worked closely with AST SpaceMobile for six years, and has helped lobby the Federal Communications Commission for the permission direct-to-smartphone satellite players still need to provide commercial services in the United States.

Earlier this month, AST SpaceMobile also announced a definitive revenue-sharing agreement with AT&T that extends to 2030.

Wisniewski said AST SpaceMobile plans to unveil its go-to-market strategies nearer commercial launch, including the benefit of pooling nearby terrestrial radio waves from AT&T and Verizon.

Following multiple production setbacks, the venture’s Block 1 satellites are slated to be delivered to Cape Canaveral by the end of August for a SpaceX Falcon 9 launch to low Earth orbit.

A Block 1 satellite would have 10 times the capacity of the company’s 1,500-kilogram BlueWalker-3 prototype — which achieved download rates of about 14 megabits per second during tests in September on AT&T spectrum — despite being roughly the same size.

The first Block 2 BlueBird satellite, which would be twice as big and have 10 times the capacity of a Block 1 BlueBird, has a launch window running from December to March.

According to AST SpaceMobile, between 45-60 BlueBirds are needed for continuous coverage in the United States.

The company said last month that it had received three non-binding letters of interest for export credit agency funding to help deploy up to 45 satellites by the end of 2026.

AST SpaceMobile raised $417 million in 2021 by listing on the stock market via a merger with a special purpose acquisition company (SPAC), a shell company that raises capital from public investors in search of an investment opportunity.

However, production delays and cost overruns have been cutting into cash reserves.

Meanwhile, SpaceX plans to start limited texting services from modified Starlink broadband satellites later this year in the United States, using T-Mobile’s radio waves in the 1900 megahertz band.

Lynk Global has started providing intermittent direct-to-smartphone texting services in the Solomon Islands, Cook Islands, and Palau with a handful of operational satellites.

The Falls Church, Virginia-based company, which has not detailed plans for the United States, is plotting its own SPAC merger to raise funds for expanding the constellation.

https://spacenews.com/verizon-plots-100-million-direct-to-smartphone-satellite-investment/

>>20932946

>>20932988

https://www.brevardfl.gov/CountyCommission

https://brevardfl.granicus.com/player/clip/448?view_id=1&redirect=true