Astronomy

Plastic production is responsible for more greenhouse gas emissions than flying – at a summit in Canada, countries were divided on how to deal with this under-recognised part of the plastic problem

Plastic production is responsible for more greenhouse gas emissions than flying – at a summit in Canada, countries were divided on how to deal with this under-recognised part of the plastic problem

Red foxes and Arctic foxes dive headfirst into snow at up to 4 metres per second to catch small rodents, and the shape of their snouts reduces the impact force

Red foxes and Arctic foxes dive headfirst into snow at up to 4 metres per second to catch small rodents, and the shape of their snouts reduces the impact force

The atlas, which is available in Chinese and English, depicts the surface of the moon with a scale of 1:2.5 million. It highlights many intriguing geological features, such as impact craters.

When a spacecraft arrives at its destination, it settles into an orbit for science operations. But after the primary mission is complete, there might be other interesting orbits where scientists would like to explore. Maneuvering to a different orbit requires fuel, limiting a spacecraft’s number of maneuvers.

Researchers have discovered that some orbital paths allow for no-fuel orbital changes. But the figuring out these paths also are computationally expensive. Knot theory has been shown to find these pathways more easily, allowing the most fuel-efficient routes to be plotted. This is similar to how our GPS mapping software plots the most efficient routes for us here on Earth.

In mathematics, knot theory is the study of closed curves in three dimensions. Think of it as looking at a knotted necklace or a tangle of fishing line, and figuring out how to untangle them in the most efficient manner.

In the same way, a spacecraft’s path could be computed in a crowded planetary system – around Jupiter and all its moons, for example – where the best, simplest and least tangled route could be computed mathematically.

A graphic showing the orbital path the Danuri Lunar Pathfinder spacecraft will take to go into orbit around the Moon. Credit: Korea Aerospace Research Institute (KARI)

According to a new paper in the journal Astrodynamics, “Applications of knot theory to the detection of heteroclinic connections between quasi-periodic orbits,” using knot theory to untangle complicated spacecraft routes would decrease the amount of computer power or just plain guesswork in plotting out changes in spacecraft orbits.

“Previously, when the likes of NASA wanted to plot a route, their calculations relied on either brute force or guesswork,” said Danny Owen, a postgraduate research student in astrodynamics, in a press release from the University of Surrey. “Our new technique neatly reveals all possible routes a spacecraft could take from A to B, as long as both orbits share a common energy level.”

Owen added that this new process makes the task of planning missions much simpler. “We think of it as a tube [subway] map for space,” he said.

Spacecraft navigation is complicated by the fact that nothing in space is a fixed position. Navigators must meet the challenges of calculating the exact speeds and orientations of a rotating Earth, a rotating target destination, as well as a moving spacecraft, while all are simultaneously traveling in their own orbits around the Sun.

Since fuel is a limited resource for most missions, it would be beneficial to require the least amount of fuel possible in making any changes to the course of a spacecraft in orbit.  

Spacecraft navigators use something called heteroclinic orbits — often called heteroclinic connections — which are paths that allow a spacecraft to travel from one orbit to another using the most efficient amount of fuel – or sometimes no fuel at all. But this usually takes a large amount of computer power or a lot of time to figure out.  

Artist’s impession of the Lunar Gateway with the Orion spacecraft docked on the left side. Credit: ESA

But Owen and co-author Nicola Baresi, a lecturer in Orbital Mechanics at the University of Surrey, wrote that by using knot theory, they have developed “a method of robustly detecting heteroclinic connections,” they wrote in their paper, to quickly generate rough trajectories – which can then be refined. This gives spacecraft navigators a full list of all possible routes from a designated orbit, and the one that best fits the mission can be chosen. They can then choose the one that best suits their mission.

The researchers tested their technique on various planetary systems, including the Moon, and the Galilean moons of Jupiter.

“Spurred on by NASA’s Artemis program, the new Moon race is inspiring mission designers around the world to research fuel-efficient routes that can better and more efficiently explore the vicinity of the Moon,” said Baresi. “Not only does our technique make that cumbersome task more straightforward, but it can also be applied to other planetary systems, such as the icy moons of Saturn and Jupiter.”

The post How Knot Theory Can Help Spacecraft Can Change Orbits Without Using Fuel appeared first on Universe Today.

The list of chemicals found in space is growing longer and longer. Astronomers have found amino acids and other building blocks of life on comets, asteroids, and even floating freely in space. Now, researchers have found another complex chemical to add to the list.

The new chemical is known as 2-methoxyethanol (CH3OCH2CH2OH). It’s one of several methoxy molecules that scientists have found in space. But with 13 atoms, it’s one of the largest and most complex ones ever detected.

A team of scientists called the McGuire Group specializes in detecting chemicals in space. The McGuire Group and other researchers from institutions in Florida and France worked together to find 2-methoxyethanol.

The researchers published their findings in The Astrophysical Journal Letters. It’s titled “Rotational Spectrum and First Interstellar Detection of 2-methoxyethanol Using ALMA Observations of NGC 6334I.” The lead author is Zachary Fried, a graduate student in the McGuire Group at MIT.

A ball and stick model of 2-methoxyethanol (CH3OCH2CH2OH). With 13 atoms, it’s one of the largest complex chemicals ever found in space. Image Credit: By Ben Mills – Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=3081683

“There are a number of ‘methoxy’ molecules in space, like dimethyl ether, methoxymethanol, ethyl methyl ether, and methyl formate, but 2-methoxyethanol would be the largest and most complex ever seen,” said lead author Fried.

The researchers didn’t stumble upon the large molecule. It was found as part of a concerted effort to detect new chemicals in space. It all started with machine learning. In 2023, one machine-learning model suggested they look for 2-methoxyethanol. The next step was the lab, where researchers performed experiments that measured and analyzed the molecule’s rotational spectrum here on Earth.

“We do this by looking at the rotational spectra of molecules, the unique patterns of light they give off as they tumble end-over-end in space,” said Fried. “These patterns are fingerprints (barcodes) for molecules. To detect new molecules in space, we first must have an idea of what molecule we want to look for, then we can record its spectrum in the lab here on Earth, and then finally we look for that spectrum in space using telescopes.”

The researchers measured the molecule’s spectrum over a broadband region of frequencies ranging from the microwave to sub-millimetre wave regimes (from about 8 to 500 gigahertz).

With that data in hand, the researchers turned to ALMA, the Atacama Large Millimetre/sub-millimetre Array. ALMA gathered data from two star-forming regions: NGC 6334I and IRAS 16293-2422B. Researchers from the McGuire Group, the National Radio Astronomy Observatory, and the University of Copenhagen all worked on analyzing ALMA’s observations.

“Ultimately, we observed 25 rotational lines of 2-methoxyethanol that lined up with the molecular signal observed toward NGC 6334I (the barcode matched!), thus resulting in a secure detection of 2-methoxyethanol in this source,” said Fried. “This allowed us to then derive physical parameters of the molecule toward NGC 6334I, such as its abundance and excitation temperature. It also enabled an investigation of the possible chemical formation pathways from known interstellar precursors.”

NGC 6334m the Cat’s Paw Nebula. Image Credit: ESO

Here on Earth, 2-methoxyethanol is used mostly as a solvent. It’s toxic to bone marrow and testicles. But its status here on Earth isn’t relevant to its discovery.

The large molecule isn’t a building block for life, either. It’s significant because of its size and complexity. Scientists are interested in understanding how chemistry evolves and forms large molecules in regions where stars and planets are forming.

“Our group tries to understand what molecules are present in regions of space where stars and solar systems will eventually take shape,” explained Fried. “This allows us to piece together how chemistry evolves alongside the process of star and planet formation.”

Molecular complexity is the hallmark of life, so, of course, scientists want to understand molecular complexity in space. As of 2021, scientists only found six molecules in space larger than 13 atoms outside our Solar System. McGuire’s team found many of them.

Finding them is the first step. The next step is to figure out how and where they form. Though there are no direct links between 2-methoxyethanol and life, all complex chemistry has something to tell us about complex chemistry in general.

“Continued observations of large molecules and subsequent derivations of their abundances allows us to advance our knowledge of how efficiently large molecules can form and by which specific reactions they may be produced,” said Fried. “Additionally, since we detected this molecule in NGC 6334I but not in IRAS 16293-2422B, we were presented with a unique opportunity to look into how the differing physical conditions of these two sources may be affecting the chemistry that can occur.”

IRAS 16293?2422 in the star-forming region Rho Ophiuchi. Image Credit: ESO

NGC 6334I is a higher-mass star-forming region compared to IRAS 16293-2422B. That means it could have a potentially enhanced radiation field. That enhanced radiation could produce more precursors for 2-methoxyethanol, eventually leading to more of the molecule itself. Warmer dust temperatures may have contributed, too. Warmer dust allows greater dust mobility, leading to chemical fragments being allowed to recombine.

Thanks to ever-improving observational tools and methods, including machine learning, astrochemistry is a blossoming field. If we’re ever going to understand how life on Earth arose and where it may likely rise elsewhere in the galaxy, astrochemistry will play a leading role. Though 2-methoxyethanol isn’t directly related to life, its detection still tells scientists something.

The post Another New Molecule Discovered Forming in Space appeared first on Universe Today.

What would happen if our closest neighbor, the moon, disappeared? Here we explore the possible effects it could have on the environment and life on Earth.

Genomic analysis suggests that the outbreak probably began in December or January, but a shortage of data is hampering efforts to pin down the source

Rising from turbulent waves of dust and gas is the Horsehead Nebula, otherwise known as Barnard 33, which resides roughly 1,300 light-years away. The NASA/ESA/CSA James Webb Space Telescope has captured the sharpest infrared images to date of one of the most distinctive objects in our skies, the Horsehead Nebula. Webb’s new view focuses on the illuminated edge of the top of the nebula’s distinctive dust and gas structure.

The James Webb Telescope has zoomed in on the Horsehead Nebula, capturing slices of this stunning star-forming region close to Earth in an entirely new light.

With an injection of rat cells, mouse brains that were genetically engineered to be unable to smell could detect odors and even track down an Oreo cookie stash

“Energy independence” doesn’t mean what politicians think it means

China reportedly plans to launch its Chang'e 6 sample-return mission toward the moon's mysterious far side on Friday (May 3).

Climate change means many tree species planted today in Europe won’t survive to the end of the century, but English oaks could thrive in many areas

Climate change means many tree species planted today in Europe won’t survive to the end of the century, but English oaks could thrive in many areas

Boeing Starliner's 1st astronaut crew continues their training, even in quarantine. After finishing a big dress rehearsal on April 26, practice continues ahead of the scheduled May 6 launch to the ISS.

A giant impact likely formed Pluto's heart-shaped basin, Sputnik Planitia. A big chunk of the impactor’s core might still be buried under the ice.

The post A Cosmic Arrow Pierced Pluto's Heart — Is It Still There Beneath the Surface? appeared first on Sky & Telescope.

NASA astronauts Barry "Butch" Wilmore and Suni Williams are slated to launch on Boeing’s first crewed test flight of its Starliner capsule, flying to the International Space Station on May 6.

The JWST is flexing its muscles with its interferometry mode. Researchers used it to study a well-known extrasolar system called PDS 70. The goal? To test the interferometry mode and see how it performs when observing a complex target.

The mode uses the telescope’s NIRISS (Near Infrared Imager and Slitless Spectrograph) as an interferometer. It’s called Aperture Masking Interferometry (AMI) and it allows the JWST to reach its highest level of spatial resolution.

A team of astronomers used the JWST’s AMI to observe the PDS 70 system. PDS 70 is a young T-Tauri star about 5.4 million years old. At that young age, its protoplanetary disk still surrounds it. PDS 70 is a well-studied system that’s caught the attention of astronomers. It’s unique because its two planets, PDS 70 b and c, make it the only multiplanet protoplanetary disk system we know of.

The researchers wanted to determine how easily the AMI would find PDS 70’s two known planets and what else it could observe in the system.

Their research is “The James Webb Interferometer: Space-based interferometric detections of PDS 70 b and c at 4.8 µm.” It’s available on the pre-print site arxiv.org and hasn’t been peer-reviewed yet. The lead author is Dori Blakely from the Department of Physics and Astronomy at the University of Victoria, BC, Canada.

PDS 70 is known for its pair of planets. PDS 70 b is about 3.2 Jupiter masses and follows a 123-year orbital period. PDS 70 c is about 7.5 Jupiter masses and follows a 191-year orbit. One of the most puzzling things about the system is that PDS 70 b appears to have its own accretion disk. The system also shows intriguing evidence of a third body, maybe another star.

The JWST’s interferometry easily detected both planets. In fact, the observations found evidence of circumplanetary disk emissions around PDS 70 b and c. “Our photometry of both PDS 70 b and c provide evidence for circumplanetary disk emission,” the researchers write. That means we can see the star and its protoplanetary disk, where planets form, and the individual circumplanetary disks around each planet. Those disks are where moons form, and seeing them in a system 366 light-years away is very impressive.

The PDS 70 system as seen by the JWST’s interferometry mode and after extensive data processing. A yellow star marks the location of PDS 70, with PDS 70 b and c also shown. The JWST shows the infrared emissions coming from the disk. Image Credit: Blakely et al. 2024.

The JWST’s AMI observations also found a third point source. Its light is different from the light from the pair of planets and more similar to the light from the star. If it’s another planet, its composition is different from the others. If it’s not another planet, that doesn’t mean it necessarily has to be another star. The JWST could be seeing scattered starlight from another gaseous, dusty structure or clump in the disk. “This indicates that what we observe is not due to a simple inner disk structure, and may hint at a complex inner disk morphology such as a spiral or clumpy features,” the researchers explain.

The unexplained third source could be something more exotic. Previous research also identified the source and suggested that it could be an accretion stream flowing between PDS 70 b and c. “We interpret its signal in the direct vicinity of planet c as tracing the accretion stream feeding its circumplanetary disk,” the authors of the previous research wrote.

These images are from previous research that used the JWST but not its interferometry mode. The top row is from the telescope’s F187N filter, and the bottom row is from the telescope’s F480M filter. The left column shows the complete images. The middle column shows the system with the disk subtracted. The right column shows the system with the disk and both known planets extracted. What remains is a potential third planet, planet “d,” and an arm-like feature and potential accretion stream. Image Credit: V. Christiaens et al. 2024.

Or, perhaps most exciting, the source could be another planet. “Another scenario is that the signal we observe is due to an additional planet interior to the orbit of PDS 70 b,” the authors explain. “Follow-up observations will be needed to determine the nature of this emission,” the authors write.

Part of the observations’ success comes from what it didn’t detect. Protoplanetary disks are dusty and difficult to examine. The JWST has a leg up on it because it can see infrared light. When used in interferometry mode, it’s a powerful tool. The fact that it failed to detect any other planets is progress, though. “Additionally, we place the deepest constraints on additional planets,” in part of the disk. These constraints will help future researchers examine the PDS 70 system and other extrasolar systems.

The results also show another of AMI’s strengths: its ability to see into parts of the parameter space that other telescopes can’t. “Furthermore, our results show that NIRISS/AMI can reliably measure relative astrometry and contrasts of young planets in a part of parameter space (small separations and moderate to high contrasts) that is unique to this observing mode, and inaccessible to all other present facilities at 4.8 µm,” the authors explain.

The JWST has already established its place in the history of astronomy. It’s delivered on its promise and has already significantly contributed to our understanding of the cosmos. The telescope’s observations with its Aperture Masking Interferometry mode will further cement its place in history.

“Here, using the power of the James Webb Interferometer, we detect PDS 70, its outer disk, and its two protoplanets, b and c. These are the first planets detected with space-based interferometry,” the authors write.

The post JWST Uses “Interferometry Mode” to Reveal Two Protoplanets Around a Young Star appeared first on Universe Today.