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ESA – Telling time on the Moon – European Space Agency

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27/02/2023
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A new era of lunar exploration is on the rise, with dozens of Moon missions planned for the coming decade. Europe is in the forefront here, contributing to building the Gateway lunar station and the Orion spacecraft – set to return humans to our natural satellite – as well as developing its large logistic lunar lander, known as Argonaut. As dozens of missions will be operating on and around the Moon and needing to communicate together and fix their positions independently from Earth, this new era will require its own time.

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ESA’s Argonaut for lunar landing

Accordingly, space organisations have started considering how to keep time on the Moon. Having begun with a meeting at ESA’s ESTEC technology centre in the Netherlands last November, the discussion is part of a larger effort to agree a common ‘LunaNet’ architecture covering lunar communication and navigation services.

Architecture for joint lunar exploration

“LunaNet is a framework of mutually agreed-upon standards, protocols and interface requirements allowing future lunar missions to work together, conceptually similar to what we did on Earth for joint use of GPS and Galileo,” explains Javier Ventura-Traveset, ESA’s Moonlight Navigation Manager, coordinating ESA contributions to LunaNet. “Now, in the lunar context, we have the opportunity to agree on our interoperability approach from the very beginning, before the systems are actually implemented.”

European Service Module flies by the Moon

Timing is a crucial element, adds ESA navigation system engineer Pietro Giordano: “During this meeting at ESTEC, we agreed on the importance and urgency of defining a common lunar reference time, which is internationally accepted and towards which all lunar systems and users may refer to. A joint international effort is now being launched towards achieving this.”

Up until now, each new mission to the Moon is operated on its own timescale exported from Earth, with deep space antennas used to keep onboard chronometers synchronised with terrestrial time at the same time as they facilitate two-way communications. This way of working will not be sustainable however in the coming lunar environment.

Gateway over Moon

Once complete, the Gateway station will be open to astronaut stays, resupplied through regular NASA Artemis launches, culminating in a human return to the lunar surface, progressing to a crewed base near the lunar south pole. Meanwhile numerous uncrewed missions will also be in place – each Artemis mission alone will release numerous lunar CubeSats – and ESA will be putting down its Argonaut European Large Logistics Lander.

These missions will not only be on or around the Moon at the same time, but they will often be interacting as well – potentially relaying communications for one another, performing joint observations or carrying out rendezvous operations.

Moonlight – Navigation and Telecommunications for the Moon

Moonlight satellites on the way

“Looking ahead to lunar exploration of the future, ESA is developing through its Moonlight programme a lunar communications and navigation service,” explains Wael-El Daly, system engineer for Moonlight. “This will allow missions to maintain links to and from Earth, and guide them on their way around the moon and on the surface, allowing them to focus on their core tasks. But also, Moonlight will need a shared common timescale in order to get missions linked up and to facilitate position fixes.”

And Moonlight will be joined in lunar orbit by an equivalent service sponsored by NASA – the Lunar Communications Relay and Navigation System. To maximise interoperability these two systems should employ the same timescale, along with the many other crewed and uncrewed missions they will support.

Far side of the Moon

Fixing time to fix position

Jörg Hahn, ESA’s chief Galileo engineer and also advising on lunar time aspects comments: “Interoperability of time and geodetic reference frames has been successfully achieved here on Earth for Global Navigation Satellite Systems; all of today’s smartphones are able to make use of existing GNSS to compute a user position down to metre or even decimetre level.

“The experience of this success can be re-used for the technical long-term lunar systems to come, even though stable timekeeping on the Moon will throw up its own unique challenges – such as taking into account the fact that time passes at a different rate there due to the Moon’s specific gravity and velocity effects.”

How satnav works

Setting global time

Accurate navigation demands rigorous timekeeping. This is because a satnav receiver determines its location by converting the times that multiple satellite signals take to reach it into measures of distance – multiplying time by the speed of light.

All the terrestrial satellite navigation systems, such as Europe’s Galileo or the United States’ GPS, run on their own distinct timing systems, but these possess fixed offsets relative to each other down to a few billionths of a second, and also to the UTC Universal Coordinated Time global standard.

Precision timing for navigation

The replacement for Greenwich Mean Time, UTC is part of all our daily lives: it is the timing used for Internet, banking and aviation standards as well as precise scientific experiments, maintained by the Paris-based Bureau International de Poids et Mesures (BIPM).

The BIPM computes UTC based on inputs from collections of atomic clocks maintained by institutions around the world, including ESA’s ESTEC technical centre in Noordwijk, the Netherlands and the ESOC mission control centre in Darmstadt, Germany.

South pole of the Moon

Designing lunar chronology

Among the current topics under debate is whether a single organisation should similarly be responsible for setting and maintaining lunar time. And also, whether lunar time should be set on an independent basis on the Moon or kept synchronised with Earth.

The international team working on the subject will face considerable technical issues. For example, clocks on the Moon run faster than their terrestrial equivalents – gaining around 56 microseconds or millionths of a second per day. Their exact rate depends on their position on the Moon, ticking differently on the lunar surface than from orbit.

“Of course, the agreed time system will also have to be practical for astronauts,” explains Bernhard Hufenbach, a member of the Moonlight Management Team from ESA’s Directorate of Human and Robotic Exploration. “This will be quite a challenge on a planetary surface where in the equatorial region each day is 29.5 days long, including freezing fortnight-long lunar nights, with the whole of Earth just a small blue circle in the dark sky. But having established a working time system for the Moon, we can go on to do the same for other planetary destinations.”

Finally, to work together properly, the international community will also have to settle on a common ‘selenocentric reference frame’, similar to the role played on Earth by the International Terrestrial Reference Frame, allowing the consistent measurement of precise distances between points across our planet. Suitably customised reference frames are essential ingredients of today’s GNSS systems.

What is ESA’s Moonlight initiative?

“Throughout human history, exploration has actually been a key driver of improved timekeeping and geodetic reference models,” adds Javier. “It is certainly an exciting time to do that now for the Moon, working towards defining an internationally agreed timescale and a common selenocentric reference, which will not only ensure interoperability between the different lunar navigation systems, but which will also foster a large number of research opportunities and applications in cislunar space.”

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CME storm effect! Sun sparks auroras without even hitting Earth – HT Tech

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CME is one of the most influential drivers of solar storms and leads to powerful Geomagnetic storms on Earth. According to NASA, they are huge bubbles of coronal plasma threaded by intense magnetic field lines that are ejected from the Sun over the course of several hours. Although CMEs usually occur with solar flares, they can occur on their own too, and have the potential to disrupt sensitive electronics on Earth, as well as affect power grids. Surprisingly, a CME doesn’t need to strike Earth to have an effect.

Just a couple of days ago, a CME passed close by Earth and this caused, what is known as a, ‘Ripple Effect’. According to a report by spaceweather.com, the interplanetary magnetic field near Earth suddenly rotated by almost 180 degrees. This usually occurs when a CME passes by closely. Despite the CME not striking Earth, it still had a spectacular effect on our planet. Auroras were seen and captured over the Arctic Circle.

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The spaceweather.com report said, “Yesterday, March 20th, the interplanetary magnetic field (IMF) near Earth suddenly rotated by almost 180 degrees. This kind of magnetic ripple is a typical sign of a CME passing nearby. The “ripple effect” ignited colorful lights inside the Arctic Circle.”

What happens when solar particles hit the Earth?

As the particles erupted during the CME reach Earth, they interact with Earth’s magnetic field and cause the formation of Geomagnetic storms. When solar particles hit Earth, the radio communications and the power grid is affected when it hits the planet’s magnetic field. It can cause power and radio blackouts for several hours or even days. However, electricity grid problems occur only if the solar flare is extremely large.

Auroras form because of the Coronal Mass Ejection (CME) from the Sun which sends solar fares hurtling towards Earth. Geomagnetic storms are often the precursor to stunning streaks of green light across the sky known as Northern Lights or Aurora Borealis.

How NASA monitors solar activity

Among many satellites and telescopes observing the Sun currently, one is the NASA Solar Dynamics Observatory (SDO). The SDO carries a full suite of instruments to observe the Sun and has been doing so since 2010. It uses three very crucial instruments to collect data from various solar activities.

They include Helioseismic and Magnetic Imager (HMI) which takes high-resolution measurements of the longitudinal and vector magnetic field over the entire visible solar disk, Extreme Ultraviolet Variability Experiment (EVE) which measures the Sun’s extreme ultraviolet irradiance and Atmospheric Imaging Assembly (AIA) which provides continuous full-disk observations of the solar chromosphere and corona in seven extreme ultraviolet (EUV) channels.


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Uracil Has Been Found In Asteroid Ryugu Samples

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Uracil

WIkipedia

Researchers have analyzed samples of asteroid Ryugu collected by the Japanese Space Agency’s Hayabusa2 spacecraft and found uracil—one of the informational units that make up RNA, the molecules that contain the instructions for how to build and operate living organisms. Nicotinic acid, also known as Vitamin B3 or niacin, which is an important cofactor for metabolism in living organisms, was also detected in the same samples.

 

This discovery by an international team, led by Associate Professor Yasuhiro Oba at Hokkaido University, adds to the evidence that important building blocks for life are created in space and could have been delivered to Earth by meteorites. The findings were published in the journal Nature Communications.

“Scientists have previously found nucleobases and vitamins in certain carbon-rich meteorites, but there was always the question of contamination by exposure to the Earth’s environment,” Oba explained. “Since the Hayabusa2 spacecraft collected two samples directly from asteroid Ryugu and delivered them to Earth in sealed capsules, contamination can be ruled out.”

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The researchers extracted these molecules by soaking the Ryugu particles in hot water, followed by analyses using liquid chromatography coupled with high-resolution mass spectrometry. This revealed the presence of uracil and nicotinic acid, as well as other nitrogen-containing organic compounds.

“We found uracil in the samples in small amounts, in the range of 6–32 parts per billion (ppb), while vitamin B3 was more abundant, in the range of 49–99 ppb,” Oba elaborated. “Other biological molecules were found in the sample as well, including a selection of amino acids, amines and carboxylic acids, which are found in proteins and metabolism, respectively.” The compounds detected are similar but not identical to those previously discovered in carbon-rich meteorites.

The team hypothesizes that the difference in concentrations in the two samples, collected from different locations on Ryugu, is likely due to the exposure to the extreme environments of space. They also hypothesized that the nitrogen-containing compounds were, at least in part, formed from the simpler molecules such as ammonia, formaldehyde and hydrogen cyanide. While these were not detected in the Ryugu samples, they are known to be present in cometary ice—and Ryugu could have originated as a comet or another parent body which had been present in low temperature environments.

“The discovery of uracil in the samples from Ryugu lends strength to current theories regarding the source of nucleobases in the early Earth,” Oba concludes. “The OSIRIS-REx mission by NASA will be returning samples from asteroid Bennu this year, and a comparative study of the composition of these asteroids will provide further data to build on these theories.”

Contact:

Associate Professor Yasuhiro Oba
Institute of Low Temperature Science
Hokkaido University
Tel: +81-11-706-5500
Email: oba@lowtem.hokudai.ac.jp

Sohail Keegan Pinto (International Public Relations Specialist)
Public Relations Division
Hokkaido University
Tel: +81-11-706-2186
Email: en-press@general.hokudai.ac.jp

Paper:

Yasuhiro Oba, et al. Uracil in the carbonaceous asteroid (162173) Ryugu. Nature Communications. March 21, 2023.

DOI: 10.1038/s41467-023-36904-3

Funding:

The Hayabusa2 project has been led by JAXA (Japan Aerospace Exploration Agency) in collaboration with DLR (German Space Center) and CNES (French Space Center) and supported by NASA (National Aeronautics and Space Administration) and ASA (Australian Space Agency). This research is partly supported by the Japan Society for the Promotion of Science (JSPS) under KAKENHI (21H04501, 21H05414, 21J00504, 21KK0062, 20H00202); the Consortium for Hayabusa2 Analysis of Organic Solubles, supported by NASA. This study was partly conducted by the official collaboration agreement through the joint research project with JAMSTEC, Keio University and HMT Inc. This study was conducted in accordance with the Joint Research Promotion Project at the Institute of Low Temperature Science, Hokkaido University (21G008, 22G008).

Astrobiology, Astrochemistry

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How to Break the Universe and Other Adventures in UMass Astronomy

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A team of astronomers, including assistant professor Kate Whitaker, recently published research in the journal Nature that many popular publications have said “breaks the universe.” While not literally true, the team, which used the newest trove of data retrieved from the James Webb Space Telescope (JWST),  discovered that very old, very massive galaxies seem to exist on the fringes of the universe—which, according to current astronomical theory, shouldn’t be possible.

Image

Images of six candidate massive galaxies, seen 500-800 million years after the Big Bang. One of the sources (bottom left) could contain as many stars as our present-day Milky Way, but is 30 times more compact. Credit: NASA, ESA, CSA, I. Labbe (Swinburne University of Technology). Image processing: G. Brammer (Niels Bohr Institute’s Cosmic Dawn Center at the University of Copenhagen)

“Do I think we broke the universe? Well, no”, says Whitaker, “but this puzzling discovery tells us that something isn’t quite right in our models.  This discovery is a learning opportunity, opening completely unexplored parameters in space and impacting our understanding of galaxy formation and evolution at the most fundamental level.”

These six galaxies are about 13.5 billion light-years away, which means that the light the team saw was emitted 13.5 billion years ago. Put another way, the team was able to look back in time 13.5 billion years. This is exciting because the universe itself is only about 14 billion years old, which means that the team was able to observe the universe’s infancy.

It has long been thought that only very young, small galaxies would have existed 13 billion years ago because not enough time would have elapsed since the Big Bang for cosmic dust and gas to accrete into massive galaxies.

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And yet, this is exactly what the team seems to have found.

“These galaxies are impossibly massive for their epochs, suggesting an accelerated growth very early on.  It would be like seeing a picture of a toddler, when we expected to find infants.”

This upends what many astronomers considered to be largely settled matters. All that extra mass at the fringes of the universe means either the current cosmological models need significant altering or our scientific understanding of galaxy formation in the early universe is incorrect. Both options require rethinking what we know about the universe’s earliest days.

“The revelation that massive galaxy formation began extremely early in the history of the universe upends what many of us had thought was settled science,” said Joel Leja assistant professor of astronomy and astrophysics at Pennyslvania State University and one of the paper’s co-authors. “We’ve been informally calling these objects ‘universe breakers’—and they have been living up to their name so far.”

But before throwing out the old astronomy textbooks, the team needs to follow up on their initial observation with more sensitive measurements that can confirm distance and size, and whether or not all of the objects are actually galaxies.

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