Astronomy

Two countries—Slovenia and Venezuela—have lost all of their glaciers. It is a grim benchmark showing the progression of climate change

On Episode 112 of This Week In Space, Rod and Tariq talk with Rob Manning, Chief Engineer Emeritus of NASA's Jet Propulsion Laboratory, about Mars exploration and, in particular, Mars Sample Return.

An explanation of Towel Day and its meaning in the world of Douglas Adams' "The Hitchhiker's Guide to the Galaxy."

The most common test of statistical significance originated from the Guinness brewery. Here’s how it works

Jared Isaacman, the billionaire funder and commander of the Polaris Program missions, spoke on social media recently about why he wants a Hubble Space Telescope mission.

North Celestial Aurora

On May 20th, 2024, an iceberg measuring 380 square kilometers (~147 mi2) broke off the Brunt Ice Shelf in Antarctica. This event (A-83) is this region’s third significant iceberg calving in the past four years. The first came In 2021, when A-74 broke off the ice sheet, while an even larger berg named A-81 followed in 2023. The separation of this iceberg was captured by two Earth Observation satellites – the ESA’s Copernicus Sentinel-1 and NASA’s Landsat 8 satellites – which provided radar imaging and thermal data, respectively.

The iceberg has been officially designated A-83 by the U.S. National Ice Center, which assigns names based on the Antarctic quadrant where the iceberg was first sighted. Since Brunt is located in the eastern Weddell Sea, its bergs receive an ‘A’ designation while the numbers are assigned sequentially. Routine monitoring of ice shelves by satellites allows scientists to track the effects of Climate Change in remote regions like Antarctica. In particular, scientists can monitor how ice shelves retain their structural integrity in response to changing ice dynamics and increases in atmospheric and ocean temperatures.

Brightness temperature data from the U.S. Landsat 8 mission. Credit: ESA/USGS

This calving event (like its predecessors) was caused by the weakening of the ice at the McDonald Ice Rumples and the extension of the ‘Halloween Crack’ into the ice shelf. The Copernicus Sentinel-1 mission relies on radar imaging to return images throughout the year, regardless of whether it’s day or night. This is especially important during the winter when there is virtually no sunlight for six months (known as Antarctic Night). Missions like Landsat 8 rely on thermal imaging to help scientists characterize ice sheet thickness.

As the image above shows, the thinner ice appears warmer since it is closer in temperature to open water, while thicker continental ice appears darker. The temperature differences between the ocean and ice sheets also help scientists identify where the calving line is. Fortunately, the iceberg does not threaten the British Antarctic Survey’s Halley VI Research Station, an international research platform that observes Earth, atmospheric, and space weather. While it is still located on the Brunt Ice Shelf, the station was relocated in 2017 to the Caird coast after the outer ice shelf was deemed unstable.

The ongoing loss of Antarctic ice is one of the clearest indications of rising global temperatures and a dire warning. In addition to contributing to rising sea levels, coastal flooding, and extreme weather, the loss of polar ice leads to additional solar radiation being absorbed by Earth’s oceans, causing temperatures to rise further. Monitoring the polar ice sheets is vital to adaptation and mitigation strategies, as spelled out in the IPCC’s Sixth Assessment Report (AR6).

Further Reading: ESA

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The James Webb Space Telescope has found three of the universe's earliest galaxies, and they could reveal a lot about galactic dynamics. Here's how.

NASA and Boeing are still working through "complicated" issues arising from a small Starliner spacecraft helium leak. Launch is June 1, but that's pending a flight readiness review.

Four zebrafish are alive and well after nearly a month in space aboard China’s Tiangong space station. As part of an experiment testing the development of vertebrates in microgravity, the fish live and swim within a small habitat aboard the station.

While the zebrafish have thus far survived, they are showing some signs of disorientation. The taikonauts aboard Tiangong – Ye Guangfu, Li Cong, and Li Guangsu – have reported instances of swimming upside down, backward, and in circular motions, suggesting that microgravity is having an effect on their spatial awareness.

The zebrafish were launched aboard Shenzhou-18, which carried them, as well as a batch of hornwort, to orbit on April 25, 2024. The aim of the project is to create a self-sustaining ecosystem, studying the effects of both microgravity and radiation on the development and growth of these species.

As a test subject, zebrafish have several advantages. Their short reproductive and development cycle, and transparent eggs, allow scientists to study their growth quickly and effectively, and their genetic makeup shares similarities with humans, potentially offering insights that are relevant to human health. The zebrafish genome has been fully sequenced, and for these reasons zebrafish are commonly used in scientific experiments on Earth. Seeing how these well-studied creatures behave in such an extreme environment may have a lot to tell us about the life and development of vertebrates across species while exposed to microgravity.

The developmental stages of a zebrafish (danio rerio). Ed Hendel, Wikimedia Commons.

The taikonauts aboard Tiangong perform feeding and water sampling at regular intervals, and cameras allow scientists on the ground to monitor the aquarium.

This is not the first time fish have been to space. Starting in 2012, a Japanese research project brought medaka and zebrafish to the International Space Station for study in a similar aquatic habitat. The results of those studies revealed a decrease in bone density in the fish within just ten days. Human astronauts experience similar effects in orbit, though not on such quick time scales, and they can be mitigated somewhat through rigorous exercise routines.

Earlier fish in space include a mummichog aboard Skylab 3 in 1973 (and again in 1975 aboard Apollo-Soyuz), and zebrafish aboard the Soviet space station Salyut 5 in 1976. A variety of fish reached orbit aboard space shuttles in the 1990s, too.

The health and sustainability of animal life in space is a key area of research for human spaceflight efforts. If humans are to travel on long-term space missions, like those required to reach Mars, then understanding the biological implications of space travel is vital. These zebrafish are the latest in a long line of experiments undertaken in this pressing area of research.  

Learn More:

Gong Zhe “Aquatic antics: Fish exhibit disorientation in China Space Station.” CGTN.

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A new catalog of the masses and widths of 126 new exoplanets showcases the extreme and exotic nature of worlds beyond the solar system.

The hunt for new exoplanets continues. On May 23rd, an international collaboration of scientists published the NASA TESS-Keck Catalog, an effort to publicly release over 9000 radial velocity measurements collected by NASA’s space-based Transiting Exoplanet Survey Satellite (TESS) and the ground-based Keck Observatory, located in Hawai’i, and the Automated Planet Finder, located at the Lick Observatory in California. An accompanying analysis of these validated 32 new planetary candidates and found the masses of 126 confirmed planets and candidates with a wide range of masses and orbits. Let’s dig into some details.

Radial velocity (RV) measurements are a backbone of exoplanet hunting. Telescopes collect data on how a star “wobbles” by checking for a red-shift (if it’s moving toward the Earth) or blue-shift (if it’s moving away) based on the gravitational pull of an exoplanet orbiting it. If the data presents a repeating pattern, the scientists know they have a likely exoplanet candidate on their hands.

To calculate the planet’s rotational period, scientists use the frequency of the changes in light from the star. They can estimate a planet’s orbital period based on how quickly the star cycles through the red and blue shifts they would expect from a complete planetary orbit. Unfortunately, since telescope time is limited, most of the exoplanets found so far using this method have much shorter orbital periods than the Earth.

Fraser discusses the end of TESS’s first mission.

Calculating a planet’s mass is also possible using the RV method – simply by calculating the planet’s gravitational pull as it is either directly behind or in front of the star. The magnitude of the respective red or blue shift can be directly tied to the planet’s mass, causing the gravitational pull.

Some truly unique worlds are hiding in the data, with two that stood out enough to be mentioned in a press release from the Keck Observatory. One is an overweight version of a “sub-Neptune”,” while another is a rapidly orbiting “super-Earth”.” 

A “sub-Neptune” is a category of planet that is a gas giant slightly smaller than Neptune, the smallest gas giant in our solar system. A planet known as TOI-1824 falls into this category but has a unique weight – it’s 19 times as massive as Earth despite being only about 2.6 times its size. That is an extremely dense planet and well outside of the range of other typical sub-Neptunes, which typically vary between 6 and 12 times the mass of our own planet.

TESS has had plenty of data updates over its lifetime – Fraser discusses one here.

A planet in the dataset that is closer in size to our own is TOI-1798c. From the mass perspective, it’s about the same size as Earth. However, it is so close to its parent’s star that it orbits it every 12 hours. This puts it in the category of an “Ultra-short period” (USP) orbit. Typically, USPs are tidally locked to their star and blasted with massive amounts of radiation. Estimates put the solar radiation it receives from its host star at 3000 times that received by the Earth. It doesn’t sound like an enjoyable vacation spot.

Doubtless, other exoplanets are hiding in the trove of data released as part of this paper. And each of those unique systems warranted their own published paper as well. As humanity begins to collect more and more discovered exoplanets, more strange and exciting new worlds will be found. It’s a crazy galaxy out there, and we’re only just starting to explore it.

Learn More:
Keck Observatory – New Catalog Showcases a Diverse Exoplanet Landscape with Strange, Exotic Worlds
Polanski et al. – The TESS-Keck Survey. XX. 15 New TESS Planets and a Uniform RV Analysis of All Survey Targets
UT – TESS Has Found Thousands of Possible Exoplanets. Which Ones Should JWST Study?
UT – Six Planets Found Orbiting an Extremely Young Star

Lead Image:
Artist’s rendering of some of the exoplanets contained in the TESS-Keck Catalog.
Credit – W. M. Keck Observatory / Adam Makarneko

The post Marvel at the Variety of Planets Found by TESS Already appeared first on Universe Today.

The joint Chinese-Pakistani cubesat mission was released by China's Chang'e 6 lunar far side sample return spacecraft on its way to the moon.

The National Hurricane Center’s hurricane season outlook for the Atlantic Ocean forecasts 17 to 25 named storms in 2024 because of an expected combination of warm ocean temperatures and a La Niña climate pattern

In just a few short years, NASA hopes to put humans back on the lunar surface. The first moonwalk in more than 50 years is scheduled for no earlier than September 2026 as part of the Artemis III mission. In preparation, astronauts, scientists, and flight controllers are conducting simulated spacewalks here on Earth.

“Field tests play a critical role in helping us test all of the systems, hardware, and technology we’ll need to conduct successful lunar operations during Artemis missions,” said Barbara Janoiko of NASA’s Johnson Space Center. “Our engineering and science teams have worked together seamlessly to ensure we are prepared every step of the way for when astronauts step foot on the Moon again.”

Astronauts Kate Rubins and Andre Douglas donned mock spacesuits and test gear for a week of simulated moonwalking near Flagstaff, Arizona, where a volcanic desert served as a stand-in for the lunar surface.

NASA astronaut Kate Rubins observes a geology sample she collected during a simulated moonwalk.
NASA/Josh Valcarcel

The tests were multipurpose, making sure that communications protocols with mission control were effective, putting technological devices that will used by moonwalkers through their paces, and doing dry runs of science-related activities, such as gathering geology samples.

The technology tested included an augmented reality visor that could provide navigational information to astronauts, helping them stay oriented and relocate the lunar lander in an emergency.
The test also simulated the communications procedures, allowing both astronauts and ground-based- teams to work together remotely to retrieve the most valuable geological samples and problem-solve in real-time.

“During Artemis III, the astronauts will be our science operators on the lunar surface with an entire science team supporting them from here on Earth,” said Cherie Achilles, science officer for the test at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This simulation gives us an opportunity to practice conducting geology from afar in real-time.”

NASA astronaut Andre Douglas collects soil samples during the first in a series of four simulated moonwalks in Arizona. NASA/Josh Valcarcel

All told the astronauts performed four ‘moonwalks’ and six technology demonstrations over the course of the week. These activities represent the fifth in a series of field tests, and are the “highest fidelity Artemis moonwalk mission simulation to date,” according to a NASA press release.

Artemis III is targeting the lunar south pole, which is a new environment for humans, far removed from the landing sites of the Apollo mission of 1969-72. The permanently shadowed craters of the south pole are expected to hold water ice, a valuable resource in space not just as a refreshing drink, but also as a source of the primary ingredients (hydrogen and oxygen) needed to make rocket fuel.

Rubins and Douglas’s space suits were open-sleeved for the Arizona desert, but prototypes of the actual spacesuits, currently under development by Axiom Space, are also undergoing testing. Future tests will have them put through their paces underwater at NASA’s Neutral Buoyancy Laboratory in Houston, Texas.

Learn More:

“NASA Tests Technology, Practices Artemis Moonwalks in Arizona Desert.” NASA.

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Swedish Space Corporation and Perigee Aerospace to launch satellites from Esrange Space Center, Sweden in 2025, with the Blue Whale 1 microlauncher.

Rocket Lab launched the first of two satellites for NASA's PREFIRE climate change mission early Saturday morning (May 25).

Mice that were given a high dose of the antiviral drug oseltamivir phosphate, better known as Tamiflu, after prolonged and excessive noise exposure showed fewer signs of hearing loss compared with those not given the medication

Mice that were given a high dose of the antiviral drug oseltamivir phosphate, better known as Tamiflu, after prolonged and excessive noise exposure showed fewer signs of hearing loss compared with those not given the medication