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December 28, 2021December 28, 2021 by Matt Williams

New Calculations Show That an Interstellar Bussard Ramjet Drive Would Need a Magnetic Field Stretching 150 Million Kilometres

An artist's impression of a ramjet drive. Credit: NASA

In the 1960s, American physicist Robert W. Bussard proposed a radical idea for interstellar travel: a spacecraft that relied on powerful magnetic fields to harvest hydrogen directly from the interstellar medium. The high speed of this “ramjet” forces the hydrogen into a progressively constricted magnetic field until fusion occurs. The magnetic field then directs the resulting energy towards the rear of the spacecraft to generate propulsion.

As it’s come to be known, the Bussard Ramjet has since been popularized by hard science fiction writers like Poul Anderson, Larry Niven, Vernor Vinge, and science communicators like Carl Sagan. Unfortunately, a team of physicists recently analyzed the concept in more detail and concluded that Bussard’s idea is not practical. At a time when interstellar travel looks destined to become a real possibility, this analysis might seem like a wet blanket but is more of a reality check.

December 23, 2021December 23, 2021 by Matt Williams

Best Image Ever Taken of Stars Buzzing Around the Milky Way’s Supermassive Black Hole

This visible light wide-field view shows the rich star clouds in the constellation of Sagittarius (the Archer) in the direction of the centre of our Milky Way galaxy. The entire image is filled with vast numbers of stars — but far more remain hidden behind clouds of dust and are only revealed in infrared images. This view was created from photographs in red and blue light and forming part of the Digitized Sky Survey 2. The field of view is approximately 3.5 degrees x 3.6 degrees.

It all began with the discovery of Sagittarius A*, a persistent radio source located at the Galactic Center of the Milky Way that turned out to be a supermassive black hole (SMBH). This discovery was accompanied by the realization that SMBHs exist at the heart of most galaxies, which account for their energetic nature and the hypervelocity jets extending from their center. Since then, scientists have been trying to get a better look at Sag A* and its surroundings to learn more about the role SMBHs play in the formation and evolution of our galaxy.

This has been the goal of the GRAVITY collaboration, an international team of astronomers and astrophysicists that have been studying the core of the Milky Way for the past thirty years. Using the ESO’s Very Large Telescope Interferometer (VLTI), this team obtained the deepest and sharpest images to date of the region around Sag A*. These observations led to the most precise measurement yet of the black hole’s mass and revealed a never-before-seen star that orbits close to it.

December 22, 2021December 22, 2021 by Matt Williams

The Bottom of Valles Marineris Seems to Have Water Mixed in With the Regolith

Mosaic of the Valles Marineris hemisphere of Mars, similar to what one would see from orbital distance of 2500 km. Credit: NASA/JPL-Caltech

For generations, humans have dreamed of the day when we might set foot on Mars. For many others, the dream has been one of settling on Mars and creating an outpost of human civilization there. Today, it looks as though both of these dreams are getting closer to becoming a reality, as space agencies and the commercial space industry are deep into planning regular crewed missions to the Red Planet. And when planning for long-duration missions to destinations in deep space, a vital aspect is assessing the local environment.

For example, missions to Mars will need to be as self-sufficient as possible, which means using local resources to meet the needs of the mission and astronauts – a process known as in-situ resource utilization (ISRU). According to new data from the ESA-Roscomos ExoMars Trace Gas Orbiter (TGO), the massive equatorial canyon known as Valles Marineris (Valley of Mars) contains vast deposits of ice that have remained hidden to scientists until now.

December 21, 2021December 21, 2021 by Matt Williams

SpaceX is Hoping to Turn Atmospheric CO2 Into Rocket Fuel

Earth is in the midst of a climate crisis. Thanks to the way CO₂ emissions have been rising rapidly since the early 20th century, global temperatures are rising, triggering a positive feedback cycle that threatens to make it worse. According to recent analyses, even if the industrialized nations agree to slash carbon emissions drastically, global warming will not begin to slow until mid-century. For this reason, emission reduction needs to be paired with carbon capture to ensure we avoid the worst-case scenarios.

Meanwhile, there is a significant outcry from the public concerning commercial space. Whereas advocates like Elon Musk argue that increasing access to space is key to our long-term survival, critics and detractors respond by stating that commercial space “steals focus” from Earth’s problems and that rocket launches produce excessive carbon emissions. In what could be a response to these challenges, Musk recently announced that SpaceX would be starting a carbon capture (CC) program to create propellants for his rockets.

December 20, 2021December 20, 2021 by Matt Williams

Floating “Aerobats” Could be the Best way to Explore the Cloud Tops of Venus

Aircraft like the Venus Atmospheric Maneuverable Platform (VAMP) could explore the cloud tops of Venus for possible signs of life. Credit: Northrop Grumman Corp.

According to multiple lines of evidence, Venus was once a much different planet than it is today. But roughly 500 million years ago, a massive resurfacing event triggered a runaway greenhouse effect that led to the hot, poisonous, and hellish environment we see there today. Therefore, the study of Venus presents an opportunity to model the evolution of planetary environments, which can serve as a reference for what could happen in the future.

In the coming years, NASA plans to send lighter-than-air missions to Venus to explore the atmosphere above the cloud tops, where temperatures are stable and atmospheric pressure is comparable to that of Earth. With support from NASA, engineers at West Virginia University (WVU) are developing software that will enable balloon-based aerial robots (aerobots) to survey Venus’ atmosphere in small fleets.

December 17, 2021December 17, 2021 by Matt Williams

The Moon is a Barren and Desolate, but Lunar Caves Could Offer Some Shelter From the Harsh Environment

A pit in a fracture on the lunar surface. (Credit: NASA/GSFC/Arizona State University)

The dream of building a permanent settlement on the Moon: a place where humans from all walks of life can come together and give rise to a new culture and identity. A place where vital scientific research and experiments can be conducted, lunar industries created, and people can go for a little “adventure tourism.” It’s been the stuff of science fiction and speculative literature for over a century. But in the coming years, it could very well become a reality.

This presents many challenges but also opportunities for creative solutions. For years, astronomers have speculated that the perfect place to create a lunar colony is underground, specifically within pits, caves, and stable lava tubes visible and accessible from the lunar surface. According to new research from CU Boulder, preliminary results show these pits to be remarkably stable compared to conditions on the surface.

December 17, 2021December 17, 2021 by Matt Williams

Would Mars be More Habitable if it Orbited a Red Dwarf?

Artist’s rendering of an exoplanet system experiencing atmospheric escape in connection with its host star. Credit: MACH Center / Aurore Simonnet

Thanks to the explosion in discoveries made in the last decade, the study of extrasolar planets have entered a new phase. With 4,884 confirmed discoveries in 3,659 systems (and another 7,958 candidates awaiting confirmation), scientists are shifting their focus from discovery to characterization. This means examining known exoplanets more closely to determine if they possess the necessary conditions for life, as well as “biomarkers” that could indicate the presence of life.

A key consideration is how the type of star may impact a planet’s chances of developing the right conditions for habitability. Consider red dwarf stars, the most common stellar class in the Universe and a great place to find “Earth-like,” rocky planets. According to a new study by an international team of scientists, a lifeless planet in our own backyard (Mars) might have evolved differently had it orbited a red dwarf instead of the Sun.

December 15, 2021December 15, 2021 by Matt Williams

A Sun-Like Star Just Blasted out a Flare That Would be Devastating if it Happened Here

In the search for “potentially-habitable” extrasolar planets, one of the main things scientists look at is stellar activity. Whereas stars like our own, a G-type (G2V) yellow dwarf, are considered stable over time, other classes are variable and prone to flare-ups – particularly M-type red dwarf stars. Even if a star has multiple planets orbiting within its habitable zone (HZ), the tendency to periodically flare could render these planets completely uninhabitable.

According to a new study, stars like our own may not be as stable as previously thought. While observing EK Draconis, a G1.5V yellow dwarf located 110.71 light-years away, an international team of astronomers witnessed a massive coronal mass ejection that dwarfed anything we’ve ever seen in our Solar System. These observations suggest that these ejections can worsen over time, which could be a dire warning for life here on Earth.

December 14, 2021December 14, 2021 by Matt Williams

Twin Stars Prove Einstein at Least 99.99% Right

Artistic impression of the Double Pulsar system, where two active pulsars orbit each other in just 147 min. The orbital motion of these extremely dense neutrons star causes a number of relativistic effects, including the creation of ripples in spacetime known as gravitational waves. The gravitational waves carry away energy from the systems which shrinks by about 7mm per days as a result. The corresponding measurement agrees with the prediction of general relativity within 0.013%. The picture at high resolution and two alternative versions (1b, 1c) are accessible in the left column. [less] © Michael Kramer/MPIfR

More than a hundred years have passed since Einstein formalized his theory of General Relativity (GR), the geometric theory of gravitation that revolutionized our understanding of the Universe. And yet, astronomers are still subjecting it to rigorous tests, hoping to find deviations from this established theory. The reason is simple: any indication of physics beyond GR would open new windows onto the Universe and help resolve some of the deepest mysteries about the cosmos.

One of the most rigorous tests ever was recently conducted by an international team of astronomers led by Michael Kramer of the Max Planck Institute for Radio Astronomy (MPIfR) in Bonn, Germany. Using seven radio telescopes from across the world, Kramer and his colleagues observed a unique pair of pulsars for 16 years. In the process, they observed effects predicted by GR for the first time, and with an accuracy of at least 99.99%!

December 13, 2021December 13, 2021 by Matt Williams

One Feature Mars has That we Don’t: Polar Megadunes

For fans of astrophotography, Kevin M. Gill needs no introduction. Even if you’re not up on the latest astronomical news and developments, chances are you’ve still seen some of his images over the years. From beautiful artist renditions to breathtaking photographs of far-off planets, Gill has covered it all. Among the latest images available on his official Flickr page are pictures of a unique feature on Mars: the Chasma Boreale Megadunes!