NASA Astronomy Picture of the Day

September 20, 2024

A Hazy Harvest Moon

For northern hemisphere dwellers, September's Full Moon was the Harvest Moon. On September 17/18 the sunlit lunar nearside passed into shadow, just grazing Earth's umbra, the planet's dark, central shadow cone, in a partial lunar eclipse. Over the two and half hours before dawn a camera fixed to a tripod was used to record this series of exposures as the eclipsed Harvest Moon set behind Spiš Castle in the hazy morning sky over eastern Slovakia. Famed in festival, story, and song, Harvest Moon is just the traditional name of the full moon nearest the autumnal equinox. According to lore the name is a fitting one. Despite the diminishing daylight hours as the growing season drew to a close, farmers could harvest crops by the light of a full moon shining on from dusk to dawn. This September's Harvest Moon was also known to some as a supermoon, a term becoming a traditional name for a full moon near perigee.

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

NASA Greenlights Next Phase of Italian Lunar Habitat Project

September 20, 2024

A NASA review board has given the Italian space agency the green light to move ahead with the development of its MPH lunar surface habitat.

ASI and NASA signed an agreement in 2022 that saw the Italian space agency take the lead on the design of the Multi-Purpose Habitation (MPH) module.

MPH is designed to act as a home base on the lunar surface to extend a crewed mission to the Moon or as a refuge in case of emergency.

In July 2024, ASI and Thales Alenia Space, the project’s prime contractor, announced that the MPH design had passed an initial mission definition review.

The next step, they explained, would be NASA’s decision on whether to proceed with the project’s development.

On 18 September, ASI announced that a NASA Mission Concept Review (MCR) Board had decided that the design had met the required criteria of the agency’s Artemis programme and had been confirmed to have reached a level of maturity that allowed its development to move to the next phase.

The MCR board was chaired by NASA Associate Administrator for the Exploration Systems Development Mission Directorate, Catherine Koerner.

“We do not see this result as an endpoint, but rather as a starting point: from now on, we will face engineering, scientific, and technological challenges to confirm the validity of the Italian project and move forward towards the implementation phase,” said ASI president Teodoro Valente.

“It’s a race against time to ensure that our MPH habitat module is the first element in the process of permanent installations on the lunar surface.”

According to the ASI update, this phase of the project’s development will last approximately two years.

After that, construction of the first flight model will begin.

Italy’s Multi-Purpose Habitation module

The MPH lunar surface habitat will be three metres wide and six metres long with a mass of around 15 tonnes.

The habitat will feature wheels, allowing it to be positioned to support crewed missions at different locations on the lunar surface.

The habitat will be capable of supporting two astronauts for one mission per year, lasting between 7 and 30 days.

It will also be capable of supporting larger crews for short periods in case of an emergency. When the habitat is not supporting a crew, it will autonomously conduct scientific experiments.

https://europeanspaceflight.com/nasa-greenlights-next-phase-of-italian-lunar-habitat-project/

Hubble Lights the Way with New Multiwavelength Galaxy View

Sep 20, 2024

The magnificent galaxy featured in this NASA/ESA Hubble Space Telescope image is NGC 1559.

It is a barred spiral galaxy located in the constellation Reticulum, approximately 35 million light-years from Earth.

The brilliant light captured in the current image offers a wealth of information.

This picture is composed of a whopping ten different Hubble images, each filtered to collect light from a specific wavelength or range of wavelengths.

It spans Hubble’s sensitivity to light, from ultraviolet through visible light and into the near-infrared spectrum.

Capturing such a wide range of wavelengths allows astronomers to study information about many different astrophysical processes in the galaxy: one notable example is the red 656-nanometer filter used here.

Ionized hydrogen atoms emit light at this particular wavelength, called H-alpha emission.

New stars forming in a molecular cloud, made mostly of hydrogen gas, emit copious amounts of ultraviolet light that the cloud absorbs, ionizing the hydrogen gas causing it to glow with H-alpha light.

Using Hubble’s filters to detect only H-alpha light provides a reliable way to detect areas of star formation (called H II regions).

These regions are visible in this image as bright red and pink patches filling NGC 1559’s spiral arms.

These ten images come from six different Hubble observing programs, spanning from 2009 all the way up to 2024.

Teams of astronomers from around the world proposed these programs with a variety of scientific goals, ranging from studying ionized gas and star formation, to following up on a supernova, to tracking variable stars as a contribution to calculating the Hubble constant.

The data from all of these observations lives in the Hubble archive, available for anyone to use.

This archive is regularly used to generate new science, but also to create spectacular images like this one!

This new image of NGC 1559 is a reminder of the incredible opportunities that Hubble provided and continues to provide.

Along with Hubble’s observations, astronomers are using the NASA/ESA/CSA James Webb Space Telescope to continue researching this galaxy.

This Webb image from February showcases the galaxy in near- and mid-infrared light.

https://science.nasa.gov/missions/hubble/hubble-lights-the-way-with-new-multiwavelength-galaxy-view/

NASA’s Chandra Finds Galaxy Cluster That Crosses the Streams

Sep 19, 2024

Astronomers using NASA’s Chandra X-ray Observatory have found a galaxy cluster has two streams of superheated gas crossing one another.

This result shows that crossing the streams may lead to the creation of new structure.

Researchers have discovered an enormous, comet-like tail of hot gas — spanning over 1.6 million light-years long — trailing behind a galaxy within the galaxy cluster called Zwicky 8338 (Z8338 for short).

This tail, spawned as the galaxy had some of its gas stripped off by the hot gas it is hurtling through, has split into two streams.

This is the second pair of tails trailing behind a galaxy in this system. Previously, astronomers discovered a shorter pair of tails from a different galaxy near this latest one.

This newer and longer set of tails was only seen because of a deeper observation with Chandra that revealed the fainter X-rays.

Astronomers now have evidence that these streams trailing behind the speeding galaxies have crossed one another.

Z8338 is a chaotic landscape of galaxies, superheated gas, and shock waves (akin to sonic booms created by supersonic jets) in one relatively small region of space.

These galaxies are in motion because they were part of two galaxy clusters that collided with each other to create Z8338.

This new composite image shows this spectacle. X-rays from Chandra (represented in purple) outline the multimillion-degree gas that outweighs all of the galaxies in the cluster.

The Chandra data also shows where this gas has been jettisoned behind the moving galaxies.

Meanwhile an optical image from the Dark Energy Survey from the Cerro Tololo Inter-American Observatory in Chile shows the individual galaxies peppered throughout the same field of view.

The original gas tail discovered in Z8338 is about 800,000 light-years long and is seen as vertical in this image (see the labeled version).

The researchers think the gas in this tail is being stripped away from a large galaxy as it travels through the galaxy cluster.

The head of the tail is a cloud of relatively cool gas about 100,000 light-years away from the galaxy it was stripped from. This tail is also separated into two parts.

The team proposes that the detachment of the tail from the large galaxy may have been caused by the passage of the other, longer tail.

Under this scenario, the tail detached from the galaxy because of the crossing of the streams.

The results give useful information about the detachment and destruction of clouds of cooler gas like those seen in the head of the detached tail.

This work shows that the cloud can survive for at least 30 million years after it is detached. During that time, a new generation of stars and planets may form within it.

The Z8338 galaxy cluster and its jumble of galactic streams are located about 670 million light-years from Earth.

A paper describing these results appeared in the Aug. 8, 2023, issue of the Monthly Notices of the Royal Astronomical Society

https://www.nasa.gov/image-article/nasas-chandra-finds-galaxy-cluster-that-crosses-the-streams/

https://academic.oup.com/mnras/article/525/1/1365/7239302.