Astronomy

Using images captured by the European Space Agency’s Mars Express spacecraft, researchers have created a cloud atlas of Mars, to better understand the climate of the Red Planet

Using images captured by the European Space Agency’s Mars Express spacecraft, researchers have created a cloud atlas of Mars, to better understand the climate of the Red Planet

The first phase of China's moon base will be completed around 2035 near the lunar south pole, and an extended model will be built by about 2050, if all goes according to plan.

SpaceX launched the four-person Polaris Dawn mission to orbit on Tuesday (Sept. 10) to carry out the first spacewalk ever performed by private astronauts.

Sentinel-2C has completed its important first few days in space, which saw teams on the ground working around the clock to ensure the spacecraft is ready to begin its mission.

The Global Methane Budget 2024 paints a troubling picture of the current state of global methane emissions. The new report reveals that human activities are now responsible for at least two-thirds of global methane emissions.

This marks a significant increase in human-produced methane sources over the past two decades, with emissions rising by 20%, with the fastest rise occurring over the last five years.

The ESA/JAXA BepiColombo spacecraft made another flyby of its eventual target, Mercury. This is one of a series of Mercury flybys, as the spacecraft completes a complex set of maneuvers designed to deliver it to the innermost planet’s orbit. Its cameras captured some fantastic images of Mercury.

BepiColombo will eventually enter orbit around Mercury in November 2026. However, Mercury is a challenge to visit because of its proximity to the Sun and the Sun’s overwhelming gravity. To eventually orbit Mercury, the spacecraft is performing six gravity-assist flybys of the Solar System’s innermost planet. This is the 4,100 kg spacecraft’s fourth flyby.

The images are a bonus. The spacecraft’s monitoring cameras captured them, and those cameras are there to keep an eye on the spacecraft itself. But in this situation, they were able to image Mercury and some prominent craters. As BepiColombo approached and passed by Mercury, different monitoring cameras were able to capture images.

All three of BepiColombo’s monitoring cameras captured images of Mercury during the recent flyby. Many of the dual-spacecraft’s scientific instruments were also active, giving the mission personnel a chance to check their function. Image Credit: ESA/Work performed by ATG under contract to ESA/CC BY-SA 3.0 IGO

The closest approach during the recent flyby was on September 4th. BepiColombo—named after Italian scientist Giuseppe “Bepi” Colombo—came within about 165 km of Mercury’s surface. This was the first time that the spacecraft had a view of the planet’s south pole.

This image highlights Mercury’s rugged surface, featureless except for craters. BepiColombo’s MC2 captured this image from about 177 km altitude. The camera was aimed at the horizon, so the actual surface is a slightly greater distance away. North is to the lower left in this image. Image Credit: ESA/BepiColombo/MTM CC BY-SA 3.0 IGO

Even though Mercury is so close, it’s seldom visited. BepiColombo is only the third spacecraft to visit the small planet after NASA’s Mariner 10 mission in 1974/75 and Messenger mission from 2011 to 2015. Its proximity to the Sun is a complex challenge.

“BepiColombo is only the third space mission to visit Mercury, making it the least-explored planet in the inner Solar System, partly because it is so difficult to get to,” said Jack Wright, ESA Research Fellow, Planetary Scientist, and M-CAM imaging team coordinator.

“It is a world of extremes and contradictions, so I dubbed it the ‘Problem Child of the Solar System’ in the past. The images and science data collected during the flybys offer a tantalizing prelude to BepiColombo’s orbital phase, where it will help to solve Mercury’s outstanding mysteries,” said Wright.

The next flyby is only a few months away, on December 1st, 2024. The final one is on January 8th, 2025.

BepiColombo is actually two orbiters in one. Once it enters Mercury’s orbit, it’ll separate into the ESA’s Mercury Planetary Orbiter (MPO) and the JAXA-built Mercury Magnetospheric Orbiter (MMO) or Mio. The Mercury Transfer Module is the spacecraft that delivers the pair of orbiters.

This simple schematic shows the three separate spacecraft that combine to make the BepiColombo mission. Image Credit: ESA

There’s a lot we don’t know about Mercury, where it originated, and how it evolved so close to its star. The spacecraft will study Mercury physically, its form, interior, structure, geology, composition, and abundant craters. It’ll also study the planet’s exosphere.

Instead of an atmosphere, Mercury has an exosphere, a region consisting of atoms blasted off the planet’s surface by the Sun and by impacts. The exosphere is dynamic and changes according to how the solar wind interacts with the surface. Studying it is an opportunity to study planetary evolution and space weather. Understanding the exosphere is also critical to future missions, especially any potential landers, because it can affect spacecraft operations.

This image shows Mercury’s 213 km Vivaldi Crater. The two booms are the Mercury Planetary Orbiter’s medium gain antenna (top centre) and magnetometer boom (right). Image Credit: ESA/BepiColombo/MTM CC BY-SA 3.0 IGO

BepiColombo will also study Mercury’s magnetosphere and magnetic fields. Mercury’s global magnetic field is extremely weak, only about 1% as strong as Earth’s. This is mysterious since the planet seems to have a large iron core.

Mercury’s magnetosphere is also an object of interest. The powerful solar wind shapes it and prevents it from rising much above the surface. The magnetosphere is also very dynamic and quickly responds to changes in the solar wind, making it a natural laboratory to study the physics of magnetospheres. Its weakness also challenges our understanding of how planetary dynamos function.

BepiColombo was initially scheduled to reach Mercury’s orbit in December 2025. However, a problem firing its thrusters during a maneuver in April 2024 added 11 months to the mission. The revised orbital insertion will be in November 2026.

Once it reaches the rapidly moving Mercury, we’ll start to learn more than ever about this sometimes overlooked planet.

The post BepiColombo’s New Images of Mercury are Cool appeared first on Universe Today.

Nine days ago, two quite different sky icons were imaged rising together.

Tropical Storm Francine formed on Monday, ending a lull in the Atlantic hurricane season. It is expected to hit Louisiana as a hurricane

NASA's Europa Clipper astrobiology probe passed a major technical review today (Sept. 9), keeping the highly anticipated mission on track for its planned Oct. 10 launch.

Ask most people what a galaxy is made up of, and they’ll say it’s made of stars. Our own galaxy, the Milky Way, hosts between about 100 to 300 billion stars, and we can see thousands of them with our unaided eyes. But most of a galaxy’s mass is actually gas, and the extent of the gas has been difficult to measure.

Researchers have found a way to see how far that gas extends into the cosmos.

One of the foundational questions about galaxies concerns their size. If we limit our observations to stars, then our galaxy, for example, is about 26.8 kiloparsecs, or about 87,000 light-years, across. Our neighbour, Andromeda, is about 46.56 kpcs or 152,000 light-years across. But do these measurements really define the sizes?

In new research published in Nature Astronomy, researchers measured the reach of the gas that extends beyond a galaxy’s stellar population. It’s titled “An emission map of the disk–circumgalactic medium transition in starburst IRAS 08339+6517.” The lead author is Nikole Nielsen, a researcher with Swinburne University and ASTRO 3D and an Assistant Professor at the University of Oklahoma.

Galaxies have gaseous haloes that serve as reservoirs of star-forming material called the circumgalactic medium (CGM). The CGM interfaces with the intergalactic medium (IGM), which is yet more gas that exists between galaxies. The CGM is notoriously difficult to observe because it’s so diffuse and extended. But it makes up about 70% of a typical galaxy (ignoring dark matter) and plays an important role. “This diffuse reservoir of gas, the circumgalactic medium, acts as the interface between a galaxy and the cosmic web that connects galaxies,” the authors explain in their paper.

Astronomers rely on bright background objects to try to observe the CGM. Things like distant quasars, pulsars, or other galaxies can light up the gas and allow astronomers to measure its spectra. But that only works when things line up right, and it only produces a beam-like image of the galaxy.

In this new research, a team of astronomers found a different way of observing the CGM. They used the Keck Cosmic Web Imager (KCWI) on the 10-meter Keck telescope in Hawaii to observe the gas around IRAS 08339+6517. Rather than a limited, beam-like look at the gas, they were able to detect the clouds of gas well outside the typical confines of a galaxy, out to 100,000 light-years beyond the limit of the starlight that typically defines a galaxy.

“We present kiloparsec-scale-resolution integral field spectroscopy of emission lines that trace cool ionized gas from the centre of a nearby galaxy to 30 kpcs into its circumgalactic medium,” the authors write. In their paper, they explain that “… we obtain the equivalent of thousands of quasar sightlines around a single galaxy.”

IRAS 08339+6517 is a starburst galaxy about 56 kpcs away. A starburst galaxy is one that is birthing stars at an extraordinarily high rate. Hubble images show that it’s a face-on spiral galaxy, and 90% of its starlight is contained within a radius of about 2.4 kpcs. “Unlike normal spirals, it has quite extreme properties, with a star formation rate (SFR) = 12.1 solar masses yr-1) that is ~ 10 times higher than typical for its mass and stellar populations that are dominated by very young (~ 4 – 6 Myr) stars,” the authors write.

The researchers found that as the CGM extends beyond the galaxy, the physical properties of the hydrogen and oxygen in the gas changed. The change was ubiquitous at a certain distance and indicates that the gas is interacting with different energy sources.

“We found it everywhere we looked, which was really exciting and kind of surprising,” said lead author Nielsen. “We’re now seeing where the galaxy’s influence stops, the transition where it becomes part of more of what’s surrounding the galaxy, and, eventually, where it joins the wider cosmic web and other galaxies. These are all usually fuzzy boundaries.”

“But in this case, we seem to have found a fairly clear boundary in this galaxy between its interstellar medium and its circumgalactic medium,” said Professor Nielsen.

“In the CGM, the gas is being heated by something other than typical conditions inside galaxies; this likely includes heating from the diffuse emissions from the collective galaxies in the Universe, and possibly some contribution is due to shocks,” said Dr Nielsen.

The boundary is where the gas is heated differently inside the galaxy compared to outside the galaxy. Inside the galaxy’s disk, gas is being photoionized by HII (ionized atomic hydrogen) star-forming regions. At further distances, the gas is being ionized by shocks or the extragalactic UV background.

“It’s this interesting change that is important and provides some answers to the question of where a galaxy ends,” she says.

This figure from the research shows the spatial distribution of ionized gas in the CGM at kiloparsec scales. Emission from [Oiii] ?5007 in the CGM of IRAS08 extends to at least 30 kpc from the galaxy center. The blue rectangle represents the field-of-view of the KCWI pointing covering the galaxy disk (emission map not shown). HI contours indicate levels of constant HI column density from the Very Large Array, where a filament extends from IRAS08 towards a smaller companion galaxy 60 kpc away. Image Credit: Nielsen et al. 2024.

These results make a contribution to one of the most interesting issues in astronomy: How do galaxies evolve?

Gas flows into galaxies and becomes fuel for more star formation. At the same time, gas flows out from a galaxy as part of stellar feedback. There are three broad types of galaxies: starburst galaxies with extreme amounts of star formation, quenched galaxies with very little star formation, and galaxies in between. The gas in the CGM and the IGM play roles in a galaxy’s gas budget.

IRAS08 has a remarkably strong outflow of gas, but its metallicity profile is flat and shallow. Astronomers typically assume that galaxies with these metallicities and high SFRs are acquiring significant amounts of gas. Other scientific observations of IRAS08 indicate “a rapid inflow of gas to the center of the disk that is fueling the very strong starburst and subsequently strong outflows,” the authors explain.

Gas flows into galaxies along spiralling filaments. This image of a galaxy shows a stream of inflowing gas, as rendered in a supercomputer. Image Credit: MPIA (G. Stinson / A.V. Maccio)

However, IRAS 08 is a complex object that’s also interacting with a nearby galaxy. “VLA observations of the HI gas around IRAS08 identified a filament extending out to ~ 40 kpcs from the galaxy and containing 70% of the neutral gas in the system,” the authors write. This filament interacts with a neighbouring galaxy about 60 kpcs away, which is only one-tenth the mass of IRAS-08.

The authors say that this interaction with its neighbour could enhance star formation, but there’s no evidence that it’s affecting IRAS-08’s morphology. This doesn’t appear to be the first stage of an eventual merger.

Finding the boundary between the CGM and the IGM could be a critical step in understanding how gas cycles in and out of galaxies and how gas may interact with neighbours without a merger.

“The circumgalactic medium plays a huge role in that cycling of that gas,” says Dr Nielsen. “So, being able to understand what the CGM looks like around galaxies of different types – ones that are star-forming, those that are no longer star-forming, and those that are transitioning between the two –we can observe differences in this gas, which might drive the differences within the galaxies themselves, and changes in this reservoir may actually be driving the changes in the galaxy itself.”

Nature has few discrete boundaries. Everything interacts with other things, including massive galaxies. The interactions hold the key to understanding.

These results could open up a whole new window into how galaxies, gas, and stars interact and how galaxies evolve.

The post The True Size of Galaxies is Much Larger Than We Thought appeared first on Universe Today.

With Boeing's Starliner spacecraft is safely back on Earth, NASA says Crew Flight Test astronauts Butch Wilmore and Suni Williams could have returned onboard.

A global survey of more than a thousand cities shows heat and air pollution in urban environments often have a measurable influence on rainfall, creating urban "wet islands"

A global survey of more than a thousand cities shows heat and air pollution in urban environments often have a measurable influence on rainfall, creating urban "wet islands"

SpaceX's trailblazing Polaris Dawn mission will make a daring trek into Earth orbit, one that will ferry the crew through belts of radiation wrapped around our planet.

Because wildfires create their own wind patterns, they can also spawn their own weather. Here’s how it works

Here at UT, we’ve had several stories that describe the concept of a space elevator. They are designed to make it easier to get objects off Earth and into space. That, so far, has proven technically or economically infeasible, as no material is strong enough to support the structure passively, and it’s too energy-intensive to support it actively. However, it could be more viable on other worlds, such as the Moon. But what about worlds farther afield? A student team from the University of Colorado at Colorado Springs looked at the use case of a space elevator on Ceres and found that it could be done with existing technology.

Before we discuss why anyone would want to put a space elevator on Ceres, let’s first examine the technologies that would make it possible. Every space elevator design has three different components: an anchor, a tether, and a counterweight. Each would require its own technologies.

The anchor is simple enough; it’s how the system interfaces with Ceres. The surface of Ceres is primarily made of clay, which is relatively good for anchoring technologies. Luckily, the force the anchor needs to withstand is only around 300N, which is much lower than the force on Earth, given Ceres’ small mass. There have already been asteroid anchoring technologies for other missions that can provide up to 500N of force resistance, so an anchor on Ceres should prove no real challenge.

Fraser describes the general idea of a space elevator.

The tether is where the technology falls short on Earth – no material known to science can withstand the forces exerted on the tether of a passively controlled space elevator when it is tied to Earth. However, the closest we can come, something space elevator enthusiasts mention as almost a holy grail, is carbon nanotubes. In the analysis for the space elevator on Ceres, they once again came out ahead. However, the limitation of actually physically creating a long tether will still plague any space elevator design on Ceres.

The counterweight is much simpler, as it can be just a big, dumb mass. However, its mass is proportional to the necessary length of cable—the heavier the mass, the shorter the cable. So, the tradeoff between having a heavier counterweight and a shorter cable is another design consideration when considering these systems.

Calculations from the team show that, with only a little more technological development, all three main systems could be ready for installation on Ceres itself. But what advantages does it have? It could be helpful as a launching point for accessing other asteroids in the asteroid belt. Ceres also has water relatively near the surface, which is helpful for all kinds of human exploration, either as rocket fuel or biological systems. It’s also well placed to quickly get things back to Earth using Jupiter as a gravity assist.

Isaac Arthur goes into a deeper description of space elevators and their advantages.

But before it can provide any of those advantages, someone is going to have to pay for it. Estimates of the overall cost of the system total about $5.2 billion — not too far out of the range of larger-scale space exploration projects. But more than most countries are likely willing to pony up for a grand infrastructure project that hasn’t yet proven its benefit.

So, for now, any space elevator will remain in the realm of science fiction. But research like this and other ongoing technological improvements is how we will eventually push forward to that future. Whether it’s a space elevator on Ceres, on the Moon, or some other novel launch technology, someday humans will need a better way to get off Earth rather than burning dead living organisms. Hopefully, that day will come sooner rather than later.

Learn More:
Bate et al. – Analyzing the Potential of Space Elevator Technology for Sustainable Asteroid Mining
UT – What is a Space Elevator?
UT – A New Method for Making Graphene has an Awesome Application: A Space Elevator!
UT – A Japanese Company is About to Test a Tiny Space Elevator… in Space

Lead Image:
Artistic view of a possible space elevator.
Credit: NASA

The post Using A Space Elevator To Get Resources Off the Queen of the Asteroid Belt appeared first on Universe Today.

The moon could still be volcanically active today, according to samples brought to Earth by China's Chang'e 5 mission in December 2020.

Are humanoid robots the future of space exploration? New Scientist reporter James Woodford took NASA's Valkyrie for a spin to find out