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A remote annular solar eclipse bookends the final eclipse season for 2024. The final eclipse of the year is almost upon us. If skies are clear, a few lucky observers and intrepid eclipse-chasers will get to witness the passage of the Moon in front of the Sun one last time on Wednesday, October 2 nd during an annular solar eclipse . The eclipse is the final one of the current season, and the last solar eclipse for 2024. The first—the April 8 th total solar eclipse spanning North America—was witnessed by millions. This week’s eclipse is by contrast much more bashful. The path and timing for Wednesday’s annular solar eclipse. Credit: from Michael Zeiler’s Atlas of Solar Eclipses (2020 to 2045) . Why Do Annulars Occur? An annular solar eclipse occurs when the Moon is visually too small to cover the Sun. Both vary in apparent size throughout the month and year, as the orbits of the Moon and the Earth are both elliptical. The shadow of the Moon falls short of the surface of the Ear...

Before you read the rest of this article know there are no known threats to life on Earth! We shouldn’t sit complacently on this tiny rock in space though so NASA have been working on ways to neutralise potential asteroid threats should they arise. The DART mission proved it was possible to alter the trajectory of an asteroid in space. Direct impact though where a probe smashes into the rock is one way but potentially not the best. A team of researchers have now been exploring ways that a nuclear explosion near an asteroid may send a blast of X-rays sufficiently powerful to vaporise material generating thrust to redirect the asteroid.  Statistically the risks of an asteroid are low but the ‘impact’ of such an event could be catastrophic. The majority of asteroids that enter our atmosphere burn up giving us the stunning sight of a ‘shooting star’  but those over 1km wide could cause widespread damage and devastation. The likelihood is rare and might occur once every several h...

I don’t think it’s something I have ever really thought of! Robotic explorers can travel around the Solar System visiting our neighbouring planets but when they arrive, sometimes a scientific package must be deployed to the surface. Never occurred to me just how that’s achieved! With a number of landers scheduled to visit the Moon, NASA are testing a new robotic arm called the Lightweight Surface Manipulation System AutoNomy capabilities Development for Surface Operations or LANDO for short! It will lift payloads off the lander and pop them down gently on the surface of the Moon.  The Moon has always held a special place in our hearts. Since the first humans saw it as they gazed up at the sky, their descendents continued the fascination with our nearest neighbour. Artists, musicians, poets and writers are among just a few of the members of our society that have reflected on its beauty. It was only natural that it would be the first target for human exploration at the dawn of spac...

The Milky Way is special because it is our home. No matter where we are on Earth we can see its arc of light overhead if the night is dark enough. But how similar is our galaxy to others? Is it an unusual spiral galaxy, or is it rather typical in the cosmos? Before we had discovered exoplanets, astronomers generally thought our solar system was rather typical. Sure, there would be differences, but the general arrangement of rocky worlds close to the Sun and cold gas giants in the outer system made sense. However when we studied planetary systems we found ours was rather unusual. Most planets orbit red dwarfs, not sun-like stars, and large gas giants often orbit close to their star. Now that we have sky surveys of galaxies throughout the Universe, we can answer the same question of the Milky way, as a recent study shows. The study is based on the Satellites Around Galactic Analogs (SAGA) Survey, which began collecting data in 2013. The goal of SAGA is to look at the small galaxies wh...

It’s great to see so many private organisations entering the space sector. Space Perspective are another and they have just completed a successful uncrewed capsule ascent to an altitude of 30km. Their Neptune-Excelsior capsule was carried by a balloon and landed in the ocean 6 hours later. It was able to maintain its cabin pressure and stability throughout the flight proving that it met the requirements for future passenger flights starting in 2025.  Space Perspective was founded in 2019 by Jane Poynter and Taber MacCallum. Their focus in the sector is space tourism and they aim to provide an accessible way for people to experience space without the need for rockets. The concept is to provide trips on board their pressurised capsules which are lifted gently to the upper atmosphere by large hydrogen filled balloons. The gentle journey is a far cry from the adrenalin fuelled rocket launches we are accustomed to seeing but still allows passengers to take in the view of the Earth fro...

Ages ago in its youth, Mars appeared much like Earth. It was a warm planet with lakes, rivers, and vast seas. It had a thick atmosphere with clouds and rain. One major difference is that the atmosphere was rich with carbon dioxide instead of oxygen. Then about 3.5 billion years ago much of the atmosphere disappeared, and we haven’t understood how. A new study in Science Advances suggests that the waters of Mars may have been the key, and much of the ancient atmosphere may be locked in the surface of the red planet. The authors center their paper on a clay mineral known as smectite. On Earth smectite is produced through tectonic activity. As tectonic plates are uplifted they can drag material from the mantle to the surface, some of which is this kind of clay. One characteristic of smectite is that it’s full of little folds. Nooks and crannies if you will, that can trap carbon dioxide for billions of years. In an earlier study the team demonstrated how smectite on Earth helped prevent...

I’ve often stated that planets come in a wide range of sizes but rarely do I find myself stating they come in a wide range of shapes too! The discovery of WASP-107b is a case  in point since this planet is the size of Jupiter but only a tenth of its mass. But there’s more… Using the James Webb Space Telescope a team of astronomers have accurately identified that the planet has an east-west asymmetry in its atmosphere, in other words, it’s lopsided. It is tidally locked to the star and on one side, the atmosphere seems to be inflated compared to the other.  Planets orbiting other stars are known as exoplanets. WASP-107b is one such planet in orbit about a star 200 light years away in the constellation of Virgo. The first exoplanet detection was confirmed in 1992 and since then over 5,000 alien planets have been identified. A multitude of different techniques are used to hunt them down from searching for dips in light from distant stars to analysing the spectra of a star. A wi...

Venus is often described as a hellscape. The surface temperature breaches the melting point of lead, and though its atmosphere is dominated by carbon dioxide, it contains enough sulfuric acid to satisfy the comparison with Hades. But conditions throughout Venus’ ample atmosphere aren’t uniform. There are locations where some of life’s building blocks could resist the planet’s inhospitable nature. Among the rocky planets, Venus has by far the largest atmosphere by volume. So, while its surface is inhospitable, its atmosphere has regions that are the most Earth-like of anywhere else in the Solar System. Scientists have wondered if life could survive in parts of the planet’s upper atmosphere, and the discovery of the potential biomarker phosphine (though it was later disproved ) generated more interest. Some research suggests that life could exist within Venus’ voluminous clouds. Image Credit: Abreu et al. 2024. One reason Venus keeps coming up in discussions around habitability is...

The reason we call dark matter dark isn’t because it’s some shadowy material. It’s because dark matter doesn’t interact with light. The difference is subtle, but important. Regular matter can be dark because it absorbs light. It’s why, for example, we can see the shadow of molecular clouds against the scattered stars of the Milky Way . This is possible because light and matter have a way to connect. Light is an electromagnetic wave, and atoms contain electrically charged electrons and protons, so matter can emit, absorb and scatter light. Dark matter isn’t electrically charged. It has no way to connect with light, and so when light and dark matter meet up they simply pass through each other. All of our observations suggest that dark matter and light only have gravity in common. When dark matter is clustered around a galaxy, for example, its gravitational tug can deflect light. Because of this we can map the distribution of dark matter in the Universe by observing how light is gravita...

We have known that water ice exists on the Moon since 1998. These large deposits are found in the permanently shadowed craters around the polar region. The challenge is how to get it since shadowed craters are not the best place for solar powered vehicles to operate. A team of engineers have identified a design for an ice-mining vehicle powered by americium-241. With a half-life of 432 years, this element is an ideal power source for a vehicle to operate in the dark for several decades.  Ice in the polar regions of the Moon is of vital importance for our future space explorations, not just lunar visits but as we stretch our legs in the Solar System. Its thought to be ancient material deposited by comets or formed by interactions with solar wind. It is expensive to take materials to the Moon so harvesting on site is far more efficient. Ice on the Moon can provide drinking water, oxygen for breaking and even hydrogen for rocket fuel. Surveys suggest something in the region of 600 b...

It’s no secret that spending extended periods in space takes a toll on the human body. For years, NASA and other space agencies have been researching the effects of microgravity on humans, animals, and plants aboard the International Space Station (ISS). So far, the research has shown that being in space for long periods leads to muscle atrophy, bone density loss, changes in vision, gene expression, and psychological issues. Knowing these effects and how to mitigate them is essential given our future space exploration goals, which include long-duration missions to the Moon, Mars, and beyond. However, according to a recent experiment led by researchers at Johns Hopkins University and supported by NASA’s Johnson Space Center, it appears that heart tissues “really don’t fare well in space” either. The experiment consisted of 48 samples of human bioengineered heart tissue being sent to the ISS for 30 days. As they indicate in their paper , the experiment demonstrates that exposure to mi...

Now is the time to catch Comet A3-Tsuchinshan-ATLAS at dawn. The window is now open. If skies are clear, set your alarm heading into this weekend to see Comet C/2023 A3 Tsuchinshan-ATLAS at dawn. We’re already seeing great views of the comet this week from southern observers and astronauts aboard the International Space Station. The visibility window is now even creeping up to the southern tier latitudes of the contiguous United States (CONUS). If fortune favors us, the comet could hit an easy naked eye magnitude +2 by next week, and forward scattering could even boost this into negative magnitudes… the rare term ‘daytime comet’ is even getting kicked around a bit in cometwatching circles. But the span to see this comet will be brief indeed. For most northern hemisphere observers, the comet will be a bashful one, never reaching much more than 10 degrees above the eastern horizon about 45 minutes before sunrise on the week centered around September 29th. Exposures of Comet A3 agai...

The most likely way we will discover life on a distant exoplanet is by discovering a biosignature . This can be done by looking at the atmospheric spectra of a world to discover the spectral pattern of a molecule that can only be created through biological processes. While it sounds straightforward it isn’t. The presence of simple molecules such as water and oxygen don’t prove life exists on a planet . It’s true that Earth’s atmosphere is oxygen rich thanks to life, but geological activity can also produce large quantities of oxygen. And as a new study shows, some molecules we’ve long thought to be biological in origin may not be. Ideally astronomers would love to find evidence of a really complex molecule such as chlorophyll. But there isn’t likely to be tons of chlorophyll in an atmosphere, so the spectral pattern would be faint, and even if it were clear the pattern is complex and hard to distinguish. So astronomers generally focus on simpler but unique molecules. One of these mol...

When a massive star explodes as a supernova, it does more than release an extraordinary amount of energy. Supernovae explosions are responsible for creating some of the heavy elements, including iron, which is blasted out into space by the explosion. On Earth, there are two accumulations of the iron isotope Fe60 in sea-floor sediments that scientists trace back about two or three million years ago and about five to six million years ago. The explosions that created the iron also dosed Earth with cosmic radiation. In new research submitted to the Astrophysical Journal Letters, scientists examine how much energy reached Earth from these explosions and how that radiation may have affected life on Earth. The paper is titled “ Life in the Bubble: How a nearby supernova left ephemeral footprints on the cosmic-ray spectrum and indelible imprints on life. ” The lead author is Caitlyn Nojiri from UC Santa Cruz. “Life on Earth is constantly evolving under continuous exposure to ionizing radi...