NASA Astronomy Picture of the Day

July 21, 2023

Galactic Cirrus: Mandel Wilson 9

The combined light of stars along the Milky Way are reflected by these cosmic dust clouds that soar 300 light-years or so above the plane of our galaxy. Known to some as integrated flux nebulae and commonly found at high galactic latitudes, the dusty galactic cirrus clouds are faint. But they can be traced over large regions of the sky toward the North and South Galactic poles. Along with the reflection of starlight, studies indicate the dust clouds produce a faint reddish luminescence as interstellar dust grains convert invisible ultraviolet radiation to visible red light. Also capturing nearby Milky Way stars and distant background galaxies, this remarkably deep, wide-field image explores a complex of faint galactic cirrus known as Mandel Wilson 9. It spans over three degrees across planet Earth's skies toward the far southern constellation Apus.

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

A mysterious source has been sending radio signals to Earth from space for decades

July 21, 2023

An unknown source has been sending radio blasts towards Earth since at least 1988, scientists say.

The researchers do not know what object is sending the radio waves towards Earth. The nature of the waves is such that they do not conform with any models that attempt to explain it.

For 35 years, the source has been sending out regular 20-minute blasts of energy that vary considerably in their brightness, researchers say.

The emissions appear something like the blasts that come out of pulsars or fast radio bursts, which last for milliseconds to several seconds. But the newly discovered source sends radio signals that pulsate on a period of 21 minutes – something previously thought impossible by expected explanations.

Pulsars are neutron stars that spin around quickly, throwing out radio blasts as they do. When one crosses Earth, the emissions can be picked up very briefly and brightly, like being in the path of the light from a rotating lighthouse.

Scientists believe that process can only work if the magnetic field of the pulsar is strong, and it is rotating quickly enough – if not, there would not be enough energy to see the pulsar from Earth. That has led to the development of the “pulsar death line”, which suggests that sources must be spinning fast and strong enough to be detected.

The newly discovered object named GPMJ1839-10, however, is way beyond that death line. If it is a pulsar, then it seems to be operating in ways that scientists thought impossible.

It could also be a highly magnetised white dwarf or magnetar, an extra kind of neutron star with incredibly strong magnetic fields. But they do not tend to send out emissions of this kind, researchers believe.

The signals have been detected on Earth since at least 1988, scientists found by going through old records, but they had gone unnoticed by those collecting that data. After the source was detected, researchers checked radio archives and found that the source has been repeating for at least 35 years.

Yet more discoveries may be made in this way in the future, said Victoria M Kaspi, a professor of physics at McGill University who did not work on the study. “Only time will tell what else lurks in these data, and what observations across many astronomical timescales will reveal,” she wrote in an accompanying article.

That might include some explanation of how unusual the newly discovered source is. By examining whether there are is a similar collection of other objects in the data, researchers might be able to understand the mechanisms behind the newly discovered emissions.

The findings are reported in a new paper, ‘A long-period radio transient active for three decades’, published in the journal Nature.

https://www.independent.co.uk/space/radio-signals-pulsar-universe-astrophysics-b2379361.html

https://www.nature.com/articles/s41586-023-06202-5#

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US, Japan host first-ever Space Engagement Talks

July 18, 2023

YOKOTA AIR BASE, Japan – The ongoing race against adversaries and competitors who possess advanced space capabilities and questionable intentions further emphasizes the need to reinforce norms of behavior in space.

U.S. Space Force Deputy Chief of Space Operations, Strategy, Plans, Programs, and Requirements, Lt. Gen. Philip A. Garrant, recently made history by leading the first-ever Space Engagement Talks with Japan, aiming to enhance combined space operations and establish a bilateral roadmap for future collaboration.

“The US-Japan Space Engagement Talks represent a further expansion of our strong alliance into the space domain,” emphasized the Commander of United States Space Forces Indo-Pacific, Brig. Gen. Anthony J. Mastalir, who hosted the event. “Through these talks and Space Working Groups to follow, we can build a roadmap for cooperation to ensure safety and security in space for our nations and all responsible actors.”

The USSF-JASDF Space Engagement Talks serve as a model of the US-Japan Alliance's commitment to space collaboration and reinforces the significance of partnerships in achieving shared objectives.

“It’s an exciting time to participate in the Space Engagement Talks with Japan,” exclaimed Mastalir. “This forum is an excellent mechanism to drive new collaborative efforts with allies and partners, and to ensure we preserve security, stability, and long-term sustainability of space for the INDOPACOM region."

The US Space Force's "Partner to Win" line of effort drives this collaboration, recognizing the strategic advantage that the global network of alliances and partnerships offers.

The potential benefits of such collaborations include greater situational awareness, improved operational effectiveness, and increased resiliency in the face of emerging threats. For example, countries with advanced space capabilities can provide technical assistance and training to those with developing space programs, while those with access to strategic locations and infrastructure can provide valuable support in areas like satellite tracking and communication.

As space continues to remain an increasingly essential domain for military operations, communication, and intelligence gathering, strong partnerships and collaborations with international allies are considered imperative for ensuring the security and safety of space-based assets.

“These talks are another example of how our two countries are working together to defend the space domain and support our bilateral joint forces,” Mastalir explained. “I’m grateful for our strong alliance with Japan and proud to be part of this important effort to advance our space operations cooperation.”

Furthermore, establishing widely accepted norms of behavior for space operations is crucial. These norms enhance the ability to attribute actions, mitigate threats, protect interests in space, and reduce the risk of strategic miscalculations. By advocating for norms of behavior in space, nations with space-based assets show a vested interest in the importance of resilience and leadership against nefarious activities.

“Through these engagements we have an opportunity to align efforts with our ally to enhance our bilateral capability in space,” highlighted Mastalir. “With representatives from U.S. Space Force Field Commands stateside and within the Indo-Pacific theater, we are able to build stronger relationships across all parts of the Space Force and normalize our presence with an important strategic ally.”

https://www.spaceforce.mil/News/Article-Display/Article/3464892/us-japan-host-first-ever-space-engagement-talks/

Celebrate 400 years of moon maps for Apollo 11's anniversary (gallery)

July 20, 2023

We've been mapping the moon in detail ever since telescopes were invented.

Humans last walked on the moon during the Apollo program, between 1969 and 1972. (And the 54th anniversary of the epic Apollo 11 landing is July 20.) NASA plans to return people to the lunar surface during the Artemis program as soon as 2025 or 2026. Getting spacecraft and people safely to the moon, however, requires high-definition imagery.

The U.S. Library of Congress gave Space.com permission to publish photos of a few of the moon maps in its possession, some of which are 400 years old. Below you can see sketches from people like Galileo, early moon photographs and pioneering spacecraft images.

Our personal histories influence how we discuss the moon. The Library of Congress is one of many U.S. museums with holdings from different cultures and genders, showcasing the diversity of viewpoints about our lunar neighbor.

At other institutions, you can view Native American interpretations of the moon at the National Museum of the American Indian. The Smithsonian Institution also has many lunar images of different cultures and genders, such as this stunning solar system quilt created in 1876 by American astronomer Ellen Harding Baker. International moon maps are also available at the University of Cambridge in England.

Italian astronomer Galileo Galilei (1564-1642) is famous for his investigations that influenced Newton's laws of motion, as well as for using and improving early telescopes. He challenged the community's view of space in that era, including that celestial objects were perfect (craters on the moon showed him otherwise) and that Earth was at the center of the universe.

Shown here is one of Galileo's first sketches of the moon, done around 1609 when such telescopic work was in its infancy. Galileo emphasized the contrast between light and dark using an artistic technique known as chiaroscuro, popularized by artists such as Caravaggio and Goya.

John Seller (1632-1697) was an English mapmaker focusing on nautical navigation who was employed by kings Charles II, James II and William III. His work includes books such as "Practical Navigation" (1669), "Atlas Maritmus" (1669) and "An Epitome of the Art of Navigation" (1681), among others. The picture here (from 1700) is from one of his lunar atlases, which he began publishing in 1680.

"While his maps often lack beauty and finesse, Seller contributed significantly to English cartography by helping to establish the market for English-language maps and charts and encouraging the growth of the cartographic industry in 17th-century England," an archived webpage from the New York Public Library states.

Johannes Hevelius (1611-1687), a Polish astronomer, made one of the first detailed atlases of the moon in 1647. The book, called "The Selenographia," includes some names for lunar mountains that are still in use, according to Britannica. He also compiled a catalog of 1,564 stars, which was the largest of its era.

Hevelius' lunar observations were helpful for navigation, particularly the search for an accurate way of measuring longitude at sea, according to Smithsonian Magazine. His detailed maps helped sailors in different locations estimate their position compared to a ground observatory, by comparing what they saw at a particular moment of time as the shadow crossed a part of the moon.

The Sea of Tranquility, where the Apollo 11 astronauts landed in 1969, was first named by Italian astronomer Giovanni Battista Riccioli (1598-1671). You can see here a moon map co-created by Riccioli and Francesco Grimaldi (1618-1663) on the right; the map on the left comes from Johannes Hevelius.

Riccioli's most famous work was "Almagestum novum" (The New Almagest), according to Oxford Reference, and it was not only for his moon mapping. Riccioli, a Jesuit priest, also presented 77 arguments against Nicolaus Copernicus, who was arguing (correctly, of course) that the sun sits at the center of our solar system.

It took a few decades for Copernicus' findings (themselves based on an ancient Greek astronomer known as Aristarchus of Somos) to be widely accepted in the astronomy community, especially since the powerful Catholic Church interpreted certain passages of the Bible to say Earth is at the center of the solar system.

German physicist Johann Tobias Mayer (1723-1762) is another lunar cartographer famous for developing maps to help sailors with navigating and with finding longitude at sea. Mayer is most famous for finding the libration (wobbling) of the moon as it orbits the Earth, according to Britannica.

The map you see here is from a lunar eclipse on August 8, 1748. It includes information in French and German showing technical data about the eclipse.

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Johann Friedrich Julius Schmidt (1825-1884) was a German astronomer and geophysicist who enjoyed studying the moon for his entire life, according to the Library of Congress. He was director of the National Observatory of Athens starting in 1858 and is famous for publishing an atlas of the moon based on maps of Wilhelm Lohrmann (1796-1840), one of whose examples is included here.

Lorhmann, the library wrote, "created a topographical series of the moon complete in 25 sheets. Schmidt edited and published all 25 sections of Lohrmann's lunar topography in 1878."

Maurice (Moritz) Loewy (1833-1907), an Austrian, received a position at the Paris Observatory in 1860 and then got French citizenship. He became director of the observatory in 1896, the same year he published an atlas of early moon pictures.

The book, co-created with French astronomer Pierre Puiseux (1855-1928), used a camera attached to a telescope. "A preset clock system was used to synchronize the camera and telescope with the lunar path," the Library of Congress stated. "The photographs were enlarged and transferred to an etching plate. Thousands of photographic prints were made from a single plate."

The first artificial satellite, the Soviet Union's Sputnik, reached Earth orbit in 1957. Soon after came both Soviet and U.S. missions to the moon to perform mapping, along with telescopic images using the best ground observatories available. The Military Geology Branch of the U.S. Geological Survey created a series of charts in July 1960 representing one of the best moon maps of the era.

Participating observatories in the effort included the McDonald Observatory (Texas), the Yerkes Observatory (Wisconsin), the Lick Observatory (California), and the Paris Observatory in France, according to the Library of Congress.

NASA's Ranger spacecraft series were also early moon explorers. The first clutch of them failed for various reasons as space engineering was in its infancy, but Rangers 7 through 9 all met their missions: to crash-land on the moon while taking pictures. The suicide dives were essential for early moon photography.

Sue Finley, an engineer at NASA's Jet Propulsion Laboratory in Southern California, led the team of women who calculated the trajectories to send the Ranger spacecraft to the moon, according to PBS. They also played key roles in a set of landing spacecraft, called Surveyor, and designed the radio antennas that formed the Deep Space Network that still communicate with spacecraft around the solar system.

Black women engineers (later known as "Hidden Figures," since their work was not much talked about for decades) worked on numerous spacecraft trajectories of the early space program as well. Mathematician Katherine Johnson, for example, created calculations allowing the two spacecraft of Apollo (the command module and lunar module) to meet up with each other in lunar orbit. NASA's headquarters is now named after Johnson.

Another keystone effort of early moon missions was the NASA Lunar Orbiter spacecraft series, which sent five missions successfully there in 1966 and 1967 to try to map the entire surface of the moon. They accomplished that goal almost entirely, mapping 99% of the surface and providing high-resolution maps useful for both crewed and uncrewed landings.

The chart shown here includes the moon's polar regions, based on photographs from each of the missions. The poles are not fully visible from Earth and represent how important spacecraft are to mapping other worlds, as well as our own.

While Apollo 17 is most famous for landing the last two people on the moon (so far) in 1972, it is also a representative mission of how humans have mapped the moon based on their own observations from up close. The map here is based upon photography taken in orbit and managed by Ron Evans, the command module pilot who did mapping and similar work while his two Apollo 17 colleagues were on the lunar surface.

The next mission to the moon, Artemis 2, includes three NASA astronauts and a Canadian astronaut. The four astronauts, led by NASA's Reid Wiseman, will launch on their round-the-moon mission no earlier than November 2024. The group includes the first of several types of folks to leave low Earth orbit: a woman (Christina Koch), a person of color (Victor Glover) and a non-American (Canadian Space Agency astronaut Jeremy Hansen.)

https://www.space.com/nasa-apollo-11-400-years-moon-mapping-gallery

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