Space News & Blog Articles

How can future lunar exploration communicate from the far side of the Moon despite never being inline with the Earth? This is what a recent study submitted to IEEE Transactions on Aerospace and Electronic Systems hopes to address as a pair of researchers from the Polytechnique Montréal investigated the potential for a wireless power transmission method (WPT) comprised of anywhere from one to three satellites located at Earth-Moon Lagrange Point 2 (EMLP-2) and a solar-powered receiver on the far side of the Moon. This study holds the potential to help scientists and future lunar astronauts maintain constant communication between the Earth and Moon since the lunar far side of the Moon is always facing away from Earth from the Moon’s rotation being almost entirely synced with its orbit around the Earth.

Here, Universe Today discusses this research with Dr. Gunes Karabulut Kurt, who is an associate professor at IEEE Polytechnique Montréal and the study’s co-author, regarding the motivation behind the study, significant results, follow-up research, and implications for WPT. So, what was the motivation behind this study?

“This research is motivated by the objective of overcoming the logistical and technical challenges associated with using traditional cables on the Moon’s surface,” Dr. Kurt tells Universe Today. “Laying cables on the Moon’s rough, dusty surface would lead to ongoing maintenance and wear problems, as lunar dust is highly abrasive. On the other hand, transporting large quantities of cables to the Moon requires a significant amount of fuel, which adds considerably to the mission’s costs.”

For the study, the researchers used a myriad of calculations and computer models to ascertain if one, two, or three satellites are sufficient within an EMLP-2 halo orbit to maintain both constant coverage of the lunar far side (LFS) and line of sight with the Earth. For context, EMLP-2 is located on the far side of the Moon with the halo orbit being perpendicular—or sideways—to the Moon’s orbit. The calculations involved in the study included the distances between each satellite, the antenna angles between the satellites and surface receiver, the amount of LFS surface coverage, and the amount of transmitted power between the satellites and LFS surface antennae. So, what were the most significant results from this study?

Dr. Kurt tells Universe Today their models concluded that three satellites in an EMLP-2 halo orbit and operating at equal distances from each other could “achieve continuous power beaming to a receiver optical antenna anywhere on the lunar far side” while maintaining 100 percent LFS coverage and line of sight with the Earth. “Aside triple satellite scheme that provides continuous LFS full coverage, even a two-satellite configuration provides full coverage during 88.60% of a full cycle around the EMLP-2 halo orbit,” Dr. Kurt adds.

Millions of people took a trip over to the US or Mexico to try and catch a glimpse of the 2024 total solar eclipse. Whether you took the trip or not, if you have since been bitten by the eclipse bug then there are three upcoming eclipses over the next couple of years. August 2026 sees an eclipse passing from Greenland, Iceland and Spain, 2027 sees an eclipse over North Africa and in 2028 Australia all be the place to be. With loads of possibilities for all locations, it’s time to get planning. 

Many people across the World make attempts to witness solar eclipses, often travelling hundreds if not thousands of kilometres. I tried such a journey back in 1999 travelling from my home in Norfolk, UK to Cornwall, a journey of over 600 kilometres. Alas, and like many eclipse chasers before me, cloud thwarted my view. However, the experience of the daylight turning to dusk in a few seconds at the onset of totality, the birds singing as the ‘Sun came out again’, it was all such an incredible amazing experience. 

Since that cloudy experience in Cornwall I committed to one day, actually seeing a total solar eclipse. I have seen partials, and they are wonderful but nothing like the majesty of a total solar eclipse.

What are we talking about? Well, the Moon travels around the Earth and the Earth travels around the Sun. It’s these changing relative positions that lead to the lunar phases. When the Moon is broadly between the Sun and Earth we experience a new moon phase. You might therefore wonder why we don’t experience a total solar eclipse every new moon! The answer lies in the obits; the orbit of the Moon around Earth is tilted by about 5 degrees in reference to the Earth’s orbit around the Sun. During most new moons the Moon is slightly above or below the Sun when viewed from Earth. It’s only when the two orbits intersect at a new moon that we see a total solar eclipse. 

This is exactly what happened on 8 April 2024, a total solar eclipse became visible as the Moon silently passed directly between the Earth and Sun. When we get a perfect alignment of three celestial bodies like this its called a Syzygy, a wonderful word and great for a game of Scrabble. Totality for this eclipse lasted for about 4 minutes depending on the location of the observer. That’s the chief difference between a solar eclipse and a lunar eclipse. Lunar eclipses are visible anywhere on Earth that the Moon is visible but solar eclipses are only visible from very specific locations on Earth. 

It’s a measure of human ingenuity and curiosity that scientists debate the possibility of life on Venus. They established long ago that Venus’ surface is absolutely hostile to life. But didn’t scientists find a biomarker in the planet’s clouds? Could life exist there, never touching the planet’s sweltering surface?

It seems to depend on who you ask.

We’ll start with phosphine.

Phosphine is a biomarker, and in 2020, researchers reported the detection of phosphine in Venus’ atmosphere. There should be no phosphine because phosphorous should be oxidized in the planet’s atmosphere. According to the paper, no abiotic source could explain the quantity found, about 20 ppb.

Subsequently, the detection was challenged. When others tried to find it, they couldn’t. Also, the original paper’s authors informed everyone of an error in their data processing that could’ve affected the conclusions. Those authors examined the issue again and mostly stood by their original detection.

Pink Floyd was wrong, there is no dark side to the Moon. There is however, a far side. The tidal effects between the Earth and Moon have caused this captured or synchronous rotation. The two sides display very different geographical features; the near side with mare and ancient volcanic flows while the far side displaying craters within craters. New research suggests the Moon has turned itself inside out with heavy elements like titanium returning to the surface. It’s now thought that a giant impact on the far side pushed titanium to the surface, creating a thinner more active near side. 

There have been a number of theories for the formation of the Moon; the capture theory and the accretion theory to name two of them. Perhaps the most accepted theory now is the giant impact theory which suggests Earth was struck by a large object, causing a lot of debris to be ejected into orbit. This material eventually coalesced to form the Moon we know and love today. 

In the decades that followed the Apollo missions, scientists studied the rocks returned by the astronauts. The studies revealed that many of the surface rocks contained unexpectedly high concentrations of titanium. More surprisingly was that satellite observations revealed these titanium rich minerals were far more common on the nearside and absent on the far-side. What is known is that the Moon formed fast and hot and would have been covered for a short period in an ocean of molten magma. The magma cooled and solidified forming the Moon’s crust but trapped below was the more dense material including titanium and iron. 

The dense material should have sunk to greater depths inside the Moon however over the years that followed something strange seems to have happened. The denser material did indeed sink, mixed with mantle but melted and returned to the surface as titanium rich lava flows. Debates have been raging whether this is exactly what happened but a new piece of research by a team at the University of Arizona Lunar and Planetary Laboratory offer more details about the process and how the interior of the Moon evolved.

It has already been suggested that the Moon may have suffered a giant impact on the far side causing the heavier elements to be forced over to the near side but the new study highlighted supporting evidence from gravitational anomalies. The team measured tiny variations in the Moon’s gravitational field from data from the GRAIL mission. GRAIL – or Gravity Recovery and Interior Laboratory – orbited the Moon to create the most accurate gravitational map of the Moon to date. Using GRAIL data the team discovered that titanium-iron oxide minerals had migrated to the near side and sunk to the interior in sheetlike cascades. This was consistent with models suggesting the event occurred more than 4.22 billion years ago. 

There’s a lot we don’t know about the planet nearest to us. Venus is shrouded in clouds, making speculation about what’s happening on its surface a parlor game for many planetary scientists for decades. But one idea that always seems to come up in those conversations – volcanoes. It’s clear that Venus has plenty of volcanoes – estimates center around about 85,000 of them in total. However, science is still unclear as to whether there is any active volcanism on Venus or not. A new set of missions to the planet will hopefully shed some light on the topic – and a new paper from researchers from Europe looks at how we might use information from those missions to do so.

The authors break the question of whether there is active volcanism on Venus into two distinct approaches. First, can Venus maintain its current atmospheric composition without adding gases from volcanic sources? Second, is there any evidence for “transient” effects that would only be possible if active volcanoes existed? 

Let’s explore the first approach first. One major data point to consider with this approach is the variability of sulfur dioxide in the atmosphere over periods as long as decades. Some researchers have pointed to this variability as clear evidence of volcanism. Still, some take a more nuanced view and point out that the variability could be caused by unknown surface-atmosphere interactions or even interactions between two layers of the atmosphere itself.

Transient effects in the atmosphere could include any number of features, ranging from water vapor to particulate matter (e.g., volcanic ash). So far, data collected on this has been limited and mainly done with remote sensing missions. However, at least a few of the new missions to Venus will involve taking data as they descend through the atmosphere. 

One of those – DAVINCI – plans to take measurements in situ in the atmosphere. It will come with a couple of spectrometers, inertial measurement units, and high-tech cameras to collect data in the planet’s lower atmosphere. The spectrometers themselves should be able to directly and clearly detect trace volcanic gases in the atmosphere. Ionic concentrations, such as the deuterium/hydrogen ratio, would also indicate ongoing volcanic outgassing.

In 2009, NASA launched the Lunar Reconnaissance Orbiter (LRO.) Its ongoing mission is to map the lunar surface in detail, locating potential landing sites, resources, and interesting features like lava tubes. The mission is an ongoing success, another showcase of NASA’s skill. It’s mapped about 98.2% of the lunar surface, excluding the deeply shadowed regions in the polar areas.

But recently, the LRO team’s skill was on display for another reason: it captured images of another satellite speeding over the lunar surface.

The Republic of Korea, or what most of us call South Korea, launched their Danuri lunar orbiter in August 2022. It’s the nation’s first lunar orbiter, and its mission is to develop and test technologies—including the space internet—and make a topographic map of the lunar surface. The map will help select future landing sites and identify resources such as uranium, helium-3, silicon, aluminum, and water ice. Danuri carries a suite of instruments, including a spectrometer, a magnetometer, and different cameras. Significantly, it contains a camera that will allow it to image the shadowed polar regions beyond the LRO’s capabilities.

NASA contributed to the Korea Aerospace Research Institute’s (KARI) Danuri mission. NASA built the Shadowcam instrument that images the shadowed regions at the lunar poles.

As a sort of high-five to their fellow space-faring nation, the LRO captured images of Danuri as it sped by under the LRO.

On Monday, April 8th, people across North America witnessed a rare celestial event known as a total solar eclipse. This phenomenon occurs when the Moon passes between the Sun and Earth and blocks the face of the Sun for a short period. The eclipse plunged the sky into darkness for people living in the Canadian Maritimes, the American Eastern Seaboard, parts of the Midwest, and northern Mexico. Fortunately for all, geostationary satellites orbiting Earth captured images of the Moon’s shadow as it moved across North America.

One such satellite was the Geostationary Operational Environmental Satellite-16 (GOES-16), part of the Earth observation network jointly run by NASA and the National Oceanic and Atmospheric Administration (NOAA). The GOES-16 (GOES-East) satellite is the first of the series, regularly monitoring space weather and providing continuous imagery and atmospheric measurements of Earth’s western hemisphere. From its orbit at a distance of 36,000 km (~22,370 mi) from Earth, GOES-16 captured the passage of the eclipse across North America from approximately 10:00 A.M. to 05:00 P.M. EST (07:00 A.M. to 02:00 P.M. PST).

Solar eclipses take several forms, which include what many residents in North America witnessed yesterday (i.e., the Moon completely blocking the face of the Sun). There’s also an annual eclipse, which happens when the Moon passes between the Sun and Earth when it is at or near its farthest point from Earth. As a result, the face of the Sun is not completely obscured and is visible as a bright ring in the sky. There’s also a partial eclipse, which happens when the Sun, Moon, and Earth are not perfectly lined up, making the Sun appear crescent-shaped.

There’s also what is known as a hybrid solar eclipse, which can appear to shift between annular and total (due to Earth’s curvature) as the Moon’s shadow moves across the globe. A total eclipse, however, is the rarest of these events, where people located directly in the center of the Moon’s shadow will see only the Sun’s outer atmosphere (the corona). The next total eclipse is not expected to occur until August 12th, 2026, and will be visible to residents in Greenland, Iceland, Spain, Russia, and a small area of Portugal. For people in Europe, Africa, and North America, the same eclipse will appear as a partial one.

The passage of the Moon’s shadow across Earth’s surface is known as the “path of totality.” As the images show, this path spanned across the North American continent from Mexico to the eastern tip of Canada. Aside from GEOS-16, images were also taken by the European Space Agency’s (ESA) Copernicus Sentinel-3 mission using its Sea and Land Surface Temperature Radiometer (SLSTR). This satellite monitors Earth’s oceans, land, glaciers, and atmosphere to monitor and improve our understanding of global weather dynamics.