NASA Astronomy Picture of the Day

May 2, 2024

M100: A Grand Design Spiral Galaxy

Majestic on a truly cosmic scale, M100 is appropriately known as a grand design spiral galaxy. The large galaxy of over 100 billion stars has well-defined spiral arms, similar to our own Milky Way. One of the brightest members of the Virgo Cluster of galaxies, M100, also known as NGC 4321 is 56 million light-years distant toward the well-groomed constellation Coma Berenices. In this telescopic image, the face-on grand design spiral shares a nearly 1 degree wide field-of-view with slightly less conspicuous edge-on spiral NGC 4312 (at upper right). The 21 hour long equivalent exposure from a dark sky site near Flagstaff, Arizona, planet Earth, reveals M100's bright blue star clusters and intricate winding dust lanes which are hallmarks of this class of galaxies. Measurements of variable stars in M100 have played an important role in determining the size and age of the Universe.

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

X-ray Satellite XMM-Newton Sees ‘Space Clover’ in a New Light

MAY 02, 2024

Astronomers have discovered enormous circular radio features of unknown origin around some galaxies. Now, new observations of one dubbed the Cloverleaf suggest it was created by clashing groups of galaxies.

Studying these structures, collectively called ORCs (odd radio circles), in a different kind of light offered scientists a chance to probe everything from supersonic shock waves to black hole behavior.

“This is the first time anyone has seen X-ray emission associated with an ORC,” said Esra Bulbul, an astrophysicist at the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, who led the study. “It was the missing key to unlock the secret of the Cloverleaf’s formation.”

A paper describing the results was published in Astronomy and Astrophysics Letters on April 30.

Until 2021, no one knew ORCs existed. Thanks to improved technology, radio surveys became sensitive enough to pick up such faint signals. Over the course of a few years, astronomers discovered eight of these strange structures scattered randomly beyond our galaxy. Each is large enough to envelop an entire galaxy –– sometimes several.

“The power needed to produce such an expansive radio emission is very strong,” Bulbul said. “Some simulations can reproduce their shapes but not their intensity. No simulations explain how to create ORCs.”

When Bulbul learned ORCs hadn’t been studied in X-ray light, she and postdoctoral researcher Xiaoyuan Zhang began poring over data from eROSITA (Extended Roentgen Survey with an Imaging Telescope Array), an orbiting German/Russian X-ray telescope. They noticed some X-ray emission that seemed like it could be from the Cloverleaf, based on less than 7 minutes of observation time.

That gave them a strong enough case to assemble a larger team and secure additional telescope time with XMM-Newton, an ESA (European Space Agency) mission with NASA contributions.

“We were allotted about five-and-a-half hours, and the data came in late one evening in November,” Bulbul said. “I forwarded it to Xiaoyuan, and he came into my office the next morning and said, ‘Detection,’ and I just started cheering!”

“We really got lucky,” Zhang said. “We saw several plausible X-ray point sources close to the ORC in eROSITA observations, but not the expanded emission we saw with XMM-Newton. It turns out the eROSITA sources couldn’t have been from the Cloverleaf, but it was compelling enough to get us to take a closer look.”

The X-ray emission traces the distribution of gas within the group of galaxies like police tape around a crime scene. By seeing how that gas has been disturbed, scientists determined that galaxies embedded in the Cloverleaf are actually members of two separate groups that drew close enough together to merge. The emission’s temperature also hints at the number of galaxies involved.

When galaxies join, their higher combined mass increases their gravity. Surrounding gas begins to fall inward, which heats up the infalling gas. The greater the system’s mass, the hotter the gas becomes.

Based on the emission’s X-ray spectrum, it’s around 15 million degrees Fahrenheit, or between 8 and 9 million degrees Celsius. “That measurement let us deduce that the Cloverleaf ORC is hosted by around a dozen galaxies that have gravitated together, which agrees with what we see in deep visible light images,” Zhang said.

The team proposes the merger produced shock waves that accelerated particles to create radio emission.

“Galaxies interact and coalesce all the time,” said Kim Weaver, the NASA project scientist for XMM-Newton at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who was not involved in the study. “But the source of the accelerated particles is unclear. One fascinating idea for the powerful radio signal is that the resident supermassive black holes went through episodes of extreme activity in the past, and relic electrons from that ancient activity were reaccelerated by this merging event.”

While galaxy group mergers are common, ORCs are very rare. And it’s still unclear how these interactions can produce such strong radio emissions.

“Mergers make up the backbone of structure formation, but there’s something special in this system that rockets the radio emission,” Bulbul said. “We can’t tell right now what it is, so we need more and deeper data from both radio and X-ray telescopes.”

The team solved the mystery of the nature of the Cloverleaf ORC, but also opened up additional questions. They plan to study the Cloverleaf in more detail to tease out answers.

https://www.nasa.gov/missions/xmm-newton/x-ray-satellite-xmm-newton-sees-space-clover-in-a-new-light/

Flexible Levitation on a Track (FLOAT)

MAY 01, 2024

We want to build the first lunar railway system, which will provide reliable, autonomous, and efficient payload transport on the Moon. A durable, long-life robotic transport system will be critical to the daily operations of a sustainable lunar base in the 2030’s, as envisioned in NASA’s Moon to Mars plan and mission concepts like the Robotic Lunar Surface Operations 2 (RLSO2), to:

— Transport regolith mined for ISRU consumables (H2O, LOX, LH2) or construction

— Transport payloads around the lunar base and to / from landing zones or other outposts

We propose developing FLOAT — Flexible Levitation on a Track — to meet these transportation needs.

The FLOAT system employs unpowered magnetic robots that levitate over a 3-layer flexible film track: a graphite layer enables robots to passively float over tracks using diamagnetic levitation, a flex-circuit layer generates electromagnetic thrust to controllably propel robots along tracks, and an optional thin-film solar panel layer generates power for the base when in sunlight. FLOAT robots have no moving parts and levitate over the track to minimize lunar dust abrasion / wear, unlike lunar robots with wheels, legs, or tracks.

FLOAT tracks unroll directly onto the lunar regolith to avoid major on-site construction — unlike conventional roads, railways, or cableways. Individual FLOAT robots will be able to transport payloads of varying shape / size (>30 kg/m^2) at useful speeds (>0.5m/s), and a large-scale FLOAT system will be capable of moving up to 100,000s kg of regolith / payload multiple kilometers per day. FLOAT will operate autonomously in the dusty, inhospitable lunar environment with minimal site preparation, and its network of tracks can be rolled-up / reconfigured over time to match evolving lunar base mission requirements.

In Phase 2, we will continue to retire risks related to the manufacture, deployment, control, and long-term operation of meter-scale robots / km-scale tracks that support human exploration (HEO) activities on the Moon, by accomplishing the following key tasks:

— Design, manufacture, and test a series of sub-scale robot / track prototypes, culminating with a demonstration in a lunar-analog testbed (that includes testing various site preparation and track deployment strategies)

— Investigate impacts of environmental effects (e.g. temperature, radiation, charging, lunar regolith simulant contamination, etc.) on system performance and longevity

— Investigate / define a technology roadmap to address technology gaps and mature manufacturing capability for critical hardware (e.g. large-area magnetic arrays with mm-scale magnetic domains, and large-area flex-circuit boards)

— Continue refining simulations of FLOAT system designs with increased fidelity, to provide improved performance estimates under the RLSO2 mission concept We will also leverage these sub-scale prototypes to explore opportunities for follow-on technology demonstrations on sub-orbital flights (via Flight Opportunities / TechFlights) or lunar technology demos (via LSII / CLPS landers)

https://www.nasa.gov/directorates/stmd/niac/niac-studies/flexible-levitation-on-a-track-float/

NASA Selects Commercial Service Studies to Enable Mars Robotic Science

MAY 01, 2024

NASA has identified nine U.S. companies to perform a total of 12 concept studies of how commercial services can be applied to enable science missions to Mars. Each awardee will receive between $200,000 and $300,000 to produce a detailed report on potential services — including payload delivery, communications relay, surface imaging, and payload hosting — that could support future missions to the Red Planet.

The companies were selected from among those that responded to a Jan. 29 request for proposals from U.S. industry.

NASA’s Mars Exploration Program initiated the request for proposals to help establish a new paradigm for missions to Mars with the potential to advance high-priority science objectives. Many of the selected proposals center on adapting existing projects currently focused on the Moon and Earth to Mars-based applications.

They include “space tugs” to carry other spacecraft to Mars, spacecraft to host science instruments and cameras, and telecommunications relays. The concepts being sought are intended to support a broad strategy of partnerships between government, industry, and international partners to enable frequent, lower-cost missions to Mars over the next 20 years.

“We’re in an exciting new era of space exploration, with rapid growth of commercial interest and capabilities,” said Eric Ianson, director of NASA’s Mars Exploration Program. “Now is the right time for NASA to begin looking at how public-private partnerships could support science at Mars in the coming decades.”

The selected Mars Exploration Commercial Services studies are divided into four categories:

Small payload delivery and hosting services

Lockheed Martin Corporation, Littleton, Colorado — adapt a lunar-exploration spacecraft

Impulse Space, Inc., Redondo Beach, California — adapt an Earth-vicinity orbital transfer vehicle (space tug)

Firefly Aerospace, Cedar Park, Texas — adapt a lunar-exploration spacecraft

Large payload delivery and hosting services

United Launch Services (ULA), LLC, Centennial, Colorado — modify an Earth-vicinity cryogenic upper stage

Blue Origin, LLC, Kent, Washington — adapt an Earth- and lunar-vicinity spacecraft

Astrobotic Technology, Inc., Pittsburgh — modify a lunar-exploration spacecraft

Mars surface-imaging services

Albedo Space Corporation, Broomfield, Colorado — adapt a low Earth orbit imaging satellite

Redwire Space, Inc., Littleton, Colorado — modify a low Earth orbit commercial imaging spacecraft

Astrobotic Technology, Inc. — modify a lunar exploration spacecraft to include imaging

Next-generation relay services

Space Exploration Technologies Corporation (SpaceX), Hawthorne, California — adapt Earth-orbit communication satellites for Mars

Lockheed Martin Corporation — provide communication relay services via a modified Mars orbiter

Blue Origin, LLC — provide communication relay services via an adapted Earth- and lunar-vicinity spacecraft

The 12-week studies are planned to conclude in August, and a study summary will be released later in the year. These studies could potentially lead to future requests for proposals but do not constitute a NASA commitment.

NASA is concurrently requesting separate industry proposals for its Mars Sample Return campaign, which seeks to bring samples being collected by the agency’s Perseverance rover to Earth, where they can be studied by laboratory equipment too large and complex to bring to Mars. The MSR industry studies are completely independent of the MEP commercial studies.

NASA’s Jet Propulsion Laboratory in Southern California manages the Mars Exploration Program on behalf of NASA’s Science Mission Directorate in Washington. The goal of the program is to provide a continuous flow of scientific information and discovery through a carefully selected series of robotic orbiters, landers, and mobile laboratories interconnected by a high-bandwidth Mars-Earth communications network. Scientific data and associated information for all Mars Exploration Program missions are archived in the NASA Planetary Data System.

https://www.nasa.gov/solar-system/planets/mars/nasa-selects-commercial-service-studies-to-enable-mars-robotic-science/