Astronomy

A new, official competition allows anyone to propose a mythology-based name for a "quasi-moon," an asteroid that orbits the Sun alongside Earth.

The post You Can Name a (Quasi) Moon! appeared first on Sky & Telescope.

The construction of the monument and another beside it more than 4,000 years ago corresponds to a time of bitter cold.

For the first time, a phenomenon astronomers have long hoped to image directly has been captured by the NASA/ESA/CSA James Webb Space Telescope’s Near-InfraRed Camera (NIRCam). In this stunning image of the Serpens Nebula, the discovery lies in the northern area of this young, nearby star-forming region.

A new species of dinosaur discovered in Montana and related to Triceratops had one of the strangest, most asymmetrical skulls that scientists have ever studied

A new species of dinosaur discovered in Montana and related to Triceratops had one of the strangest, most asymmetrical skulls that scientists have ever studied

Virgin Galactic shared an awe-inspiring video from the final flight of its VSS Unity space plane.

NASA will discuss the results of a recent asteroid-threat exercise today (June 20), and you can watch it live.

Gene-cutting diagnostic tests could be as easy as a rapid COVID test and as accurate as PCR

A completely fabricated condition, crafted from racist medical biases, still corrupts the criminal justice system today

Mathematicians picked the most dazzling, thought-provoking and compelling equations they know

Rocket Lab plans to launch its Electron vehicle for the 50th time today (June 20), and you can watch the milestone moment live.

A Doctor Who superfan explains how the unusual cardiovascular system of the alien Time Lords could evolve and function

The summer solstice, also known as the June solstice arrives June 20 at 4:51 p.m. EDT (2051 GMT), marking the longest day in the Northern Hemisphere.

ESA’s XMM-Newton and NASA’s Chandra spacecraft have detected three young neutron stars that are unusually cold for their age. By comparing their properties to different neutron star models, scientists conclude that the oddballs’ low temperatures disqualify around 75% of known models. This is a big step towards uncovering the one neutron star ‘equation of state’ that rules them all, with important implications for the fundamental laws of the Universe.

Detecting faint objects close to bright stars is incredibly difficult. Yet, by combining data from ESA's Gaia space telescope with ESO’s GRAVITY instrument on the ground, scientists managed just that. They captured the first light signals of so far unseen dim companions of eight luminous stars. The technique unlocks the tantalising possibility to capture images of planets orbiting close to their host stars.

NASA’s Perseverance Rover has left Mount Washburn behind and arrived at its next destination, Bright Angel. It found an unusual type of rock there that scientists are calling ‘popcorn rock.’ The odd rock is more evidence that water was once present in Jezero Crater.

Perseverance’s mission is centred on life on ancient Mars. Along with searching for fossilized evidence of ancient life, it’s searching for and trying to understand environments that could’ve supported life. That’s why it’s in Jezero Crater, an ancient paleolake with a delta of sediments and other intriguing geological features.

On Sol 1175 of its mission, Perseverance arrived at Bright Angel, a scientifically interesting region that’s part of the river channel that fed into Jezero Crater. Bright Angel is noted for light-toned rocky outcrops that are either ancient sediments that filled the channel or much older rock exposed by the river.

The image below shows the rover’s path leading to Bright Angel. The white portion shows where Perseverance paralleled the Neretva Vallis river channel, and the blue portion shows where it travelled through the channel. The light-toned rocks of Bright Angel are clearly visible.

This Mars Reconnaissance Orbiter image was captured by the orbiter’s HiRISE camera, and it shows the Neretva Vallis river channel with Perseverance’s route overlain. It has left Mount Washburn behind and has reached Bright Angel. Image Credit: NASA/JPL-Caltech/University of Arizona

As Perseverance worked its way toward Bright Angel, mission personnel could see the light rocks in the distance. But the route to the new destination wasn’t easy. The rover encountered a boulder field that proved so arduous that operators changed course.

“We started paralleling the channel in late January and were making pretty good progress, but then the boulders became bigger and more numerous,” said Evan Graser, Perseverance’s deputy strategic route planner lead at NASA’s Jet Propulsion Laboratory in Southern California. “What had been drives averaging over a hundred meters per Martian day went down to only tens of meters. It was frustrating.”

Perseverance has two modes of travel. In rougher terrain, the route planning team uses images to plan the rover’s route about 30 meters at a time. To travel further than that in a single sol, the team relies on Perseverance’s autopilot mode, called AutoNav. But as the route through the boulder field became more difficult, AutoNav struggled. It sometimes just stopped, which is the safest option. But that means the drive to Bright Angel was taking far longer than anticipated.

“We had been eyeing the river channel just to the north as we went, hoping to find a section where the dunes were small and far enough apart for a rover to pass between — because dunes have been known to eat Mars rovers,” said Graser. “Perseverance also needed an entrance ramp we could safely travel down. When the imagery showed both, we made a beeline for it.”

The rover was rerouted through the dune field and across the river channel, reducing its drive by several weeks.

Perseverance captured this image of Bright Angel with one of its Navcams on June 6th, 2024. Bright Angel is the light-toned area in the distance on the right. Image Credit: NASA/JPL-Caltech

Perseverance is nearing the end of its fourth science phase. It’s been searching for carbonate rocks and olivine in the Margin Unit, which is along the inside of Jezero Crater’s rim. But at Bright Angel, it hoped to find different rocks.

That’s exactly what’s happened.

According to a NASA press release, geologists were mesmerized by what they saw. Some of the rocks are densely packed with spheres, which earned them the name ‘popcorn rocks.’ The rocks are also full of ridges that look like mineral veins. Mineral veins occur when water transports minerals through rock and deposits them.

These rocks in Bright Angel have unusual popcorn-like textures and abundant mineral veins. Image Credit: NASA/JPL-Caltech/ASU

Mineral veins are common on wet, watery Earth, and rovers have spotted them elsewhere on Mars.

The MSL Curiosity rover captured this image of mineral veins in Martian rocks in 2015. The area is called Garden City, and it’s on lower Mt. Sharp in Gale Crater. Image Credit: NASA/JPL-Caltech/MSSS

The popcorn features could also be evidence of water. Like the mineral veins, they indicate that water flowed through these rocks.

The next step is to determine what minerals are present in these popcorn rocks. Perseverance will work its way up Bright Angel, taking measurements as it goes. On the weekend, it’ll use its abrasion tool and other instruments to take an even closer look. It’ll vaporize some of the rock and use its SuperCam suite of instruments to examine the rocks’ chemistry. The decision to take a sample for eventual return to Earth (hopefully) will rest on those results.

Once Perseverance is finished at Bright Angel, the rover will make its way south again, across Neretva Vallis, to its next destination: Serpentine Rapids.

The post Perseverance Found Some Strange Rocks. What Will They Tell Us? appeared first on Universe Today.

People who regularly have lower back pain go longer without the discomfort if they incorporate walks into their weekly routines

People who regularly have lower back pain go longer without the discomfort if they incorporate walks into their weekly routines

Earth is a seismically active planet, and scientists have figured out how to use seismic waves from Earthquakes to probe its interior. We even use artificially created seismic waves to identify underground petroleum-bearing formations. When the InSIGHT (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) lander was sent to Mars, it sensed Marsquakes to learn more bout the planet’s interior.

Researchers think they can use Marsquakes to answer one of Mars’ most pressing questions: Does the planet hold water trapped in its subsurface?

Ground-penetrating radar can tell us what’s underground on Earth. However, it has limitations. It can reach about 30 meters underground in low-conductivity materials and as shallow as one meter in conductive materials. Scientists are developing other methods, including seismological interferometers, to use seismology to detect deeper aquifers, but those methods are not fully developed. There’s also so much water inside Earth that it creates noisy signals.

These methods are not applicable to Mars, where equipment is limited.

However, researchers from Penn State University think they can use a different type of seismology to detect Mars’ subsurface water. It’s called the seismoelectric method, and it combines seismology and electromagnetism. It senses the electromagnetic signals that come from the propagation of seismic waves in a planet’s interior.

Their new research, “Characterizing Liquid Water in Deep Martian Aquifers: A Seismo-Electric Approach,” has been published in JGR Planets. Nolan Roth, a doctoral candidate in the Department of Geosciences at Penn State, is the lead author.

“The scientific community has theories that Mars used to have oceans and that, over the course of its history, all that water went away,” Roth said. “But there is evidence that some water is trapped somewhere in the subsurface. We just haven’t been able to find it. The idea is, if we can find these electromagnetic signals, then we find water on Mars.”

This artist’s impression shows how Mars may have looked about four billion years ago. The young planet Mars would have had enough water to cover its entire surface in a liquid layer about 140 metres deep, but it is more likely that the liquid would have pooled to form an ocean occupying almost half of Mars’s northern hemisphere and in some regions reaching depths greater than 1.6 kilometres. Credit: ESO/M. Kornmesser

Seismology works by detecting elastic waves that propagate through the Earth. These waves are divided into subtypes, especially P-waves, or primary waves, and S-waves, or secondary waves. Each type of wave travels differently depending on the material it’s moving through. In broad terms, P-waves travel faster than S-waves, so they arrive at seismographic sensors at different times. The differences in those times and other factors reveal the characteristics and densities of the material the waves are travelling through.

The seismoelectric method detects the electromagnetic signals created by seismic waves rather than the waves themselves. As the waves travel through a planet, materials like rock or water move differently in response. Those differences create magnetic fields that surface sensors can detect.

“If we listen to the marsquakes that are moving through the subsurface, if they pass through water, they’ll create these wonderful, unique signals of electromagnetic fields,” Roth said. “These signals would be diagnostic of current, modern-day water on Mars.”

This method is especially suited to Mars. On Earth, water is mixed throughout the subsurface, not just in aquifers, making detection difficult. But Mars is extremely dry, other than potential subsurface aquifers. If we detect buried water on Mars with the seismoelectric method, it’s almost certainly a subsurface aquifer.

Artist’s impression of water under the Martian surface. Credit: ESA/Medialab

“In contrast to how seismoelectric signals often appear on Earth, Mars’ surface naturally removes the noise and exposes useful data that allows us to characterize several aquifer properties,” said co-author Tieyuan Zhu, associate professor of geosciences at Penn State and Roth’s adviser.

The seismoelectric method involves two types of electromagnetic fields: co-seismic waves and interface responses (IR). There are two types of interface responses: radiating interface responses (RIRs) and evanescent interface responses (EIRs.)

“Interface responses (IRs) are generated when a seismic wave creates a charge imbalance across a saturated interface,” the authors explain. RIRs radiate from the interface independently at electromagnetic velocities, regardless of how much fluid is in the medium. EIRs are generated when a seismic wave impinges on a saturated interface at a particular angle. Both types of IRs are generated in the presence of mobile fluids, but they don’t require a saturated layer to propagate further. RIRs, in particular, can travel through kilometres of rock. The two types of interface responses can be separated and analyzed independently.

It all adds up to a new method of “seeing” inside Mars and finding saturated layers.

Roth and his co-researchers started by creating a model of subsurface Mars. Then, they added aquifers to simulate how the seismoelectric method could work. The results showed they could use the seismoelectric technique to uncover details about the aquifers, including their dimensions and chemical properties, like salinity.

“Aquifer depth, thickness, and quantity affect interface response arrival times and shape,” the authors write in their research. “Aquifer water saturation fraction, chemistry, and salinity strongly impact the interface response strength but have little to no affect on the waveform shape.”

“Seismo-electric signals can be used to constrain estimates of aquifer depth, volume, location, and bulk chemical composition,” they added.

This illustration from the research shows how the seismoelectric method could detect subsurface water on Mars. It shows three different cases: a dry Mars, a Mars with a deep aquifer, and an Earth-analog model. There’s a lot of complexity, but the main takeaway is that the different interface responses behave differently and arrive at sensors at different times. See the published research for more details. Image Credit: Roth et al. 2024.

“SE measurements give us a way to detect and image Martian groundwater kilometres below the surface,” the authors write in their conclusion. “As SE exploration becomes more widespread on Earth, this study represents the first foray of the method to other worlds.”

“If we can understand the signals, we can go back and characterize the aquifers themselves,” Roth said in a press release. “And that would give us more constraints than we’ve ever had before for understanding water on Mars today and how it has changed over the last 4 billion years. And that would be a big step ahead.”

The most exciting part about using the seismoelectric method on Mars is that it doesn’t require a new mission. NASA’s InSIGHT lander acquired ample seismic data during its mission. It also had a magnetometer, and future work will combine the signals from both to open a new window into subsurface Mars.

If the method proves fruitful, seismometers and magnetometers could be included in future missions, not only to Mars but also to other worlds. Frozen ocean moons like Europa and Enceladus are prime exploration targets in the search for life, and the technique could work there.

“This shouldn’t be limited to Mars — the technique has potential, for example, to measure the thickness of icy oceans on a moon of Jupiter,” Zhu said. “The message we want to give the community is there is this promising physical phenomena — which received less attention in the past — that may have great potential for planetary geophysics.”

The post Marsquakes Can Help Us Find Water on the Red Planet appeared first on Universe Today.

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