Space News & Blog Articles

Dust is an everyday feature on Mars and wreaks havoc on various pieces of equipment humans decide to send to it, such as Insight’s continual loss of power or the losses of Opportunity and Spirit. But we’ve never really understood what causes the dust to get up into the air in the first place. That equipment that is so affected by it usually isn’t set up to monitor it, or if it is, it has been sent to a place where there isn’t much dust, to begin with. Now, that has changed with new readings from Perseverance in Jerezo crater, and the answer shouldn’t be much of a surprise – dust devils seem to cause some of the dust in the atmosphere on Mars. But strong winds contribute a significant amount too.

A new paper in Science Advances by a team of over 45 scientists reports on data collected by Perseverance’s instrumentation that is designed to study the Martian environment. The Radiation and Dust Sensor (RDS) instrumentation is part of a broader package of instrumentation known as the Mars Environment Dynamics Analyzer (MEDA).  

This instrument can detect changes in the environmental conditions that would occur around the rover about once a second. The most likely cause of those changes would be the presence of dust devils.

UT video discussing the perils of dust storms

But it is not enough to detect those changes alone, as they could be caused by sources other than dust devils. So the RDS combines forces with another MEDA instrument, the Thermal InfraRed Sensor (TIRS), which can provide data on the tracking radiative flux around the rover. Combining these two data sets allow scientists to comprehensively say whether or not a dust devil has overtaken the rover.

They do so often. About four times a day, the rover is subjected to “convective vortices,” the technical term for updrafts that are strong enough to sense. About one of those four carries enough dust to be thought of as what we would conventionally call a “dust devil.” And their existence seems to be the source of most of the dust that reaches the air. But they aren’t the only source.

Sunspots are typically no real reason to worry, even if they double in size overnight and grow to twice the size of the Earth itself. That’s just what happened with Active Region 3038 (AR3038), a sunspot that happens to be facing Earth and could produce some minor solar flares. While there’s no cause for concern, that does mean a potentially exciting event could happen – spectacular auroras.

Although scientists consistently point out that people are in no danger from sunspots like AR3038, that doesn’t stop the popular media from worrying about them, especially ones that seem to grow quickly. But this is all par for the course, according to Rob Steenburgh, the head of the US’s National Oceanic and Atmospheric Administration Space Weather Forecast Office. 

He points out that this type of rapid growth is exactly what we expect to see at this point in the solar cycle, the 11-year repeating pattern that started again in 2019. He also points out that sunspots of this kind don’t typically produce the types of dangerous solar flares that could knock out satellites or disrupt power grids. It simply lacks the complexity.

UT video describing when we should be worried about solar flares.

Solar flares occur when the magnetic fields surrounding a sunspot break and rejoin in complex patterns, some of which cause flairs to be ejected out into the solar system. If these hit the Earth, they could potentially cause damage to some infrastructure, especially those reliant on electricity. However, they are much more likely to create spectacular auroras when their ions hit Earth’s own magnetic field.

They are rated in severity, scaling from B (the weakest) to C, M, and X (the strongest). X flares have their own grading system, and the most powerful solar flares, X20, happen less than once per 11-year solar cycle and typically do not face Earth.

The Lunar Reconnaissance Orbiter (LRO) – NASA’s eye-in-the-sky in orbit around the Moon – has found the crash site of the mystery rocket booster that slammed into the far side of the Moon back on March 4th, 2022. The LRO images, taken May 25th, revealed not just a single crater, but a double crater formed by the rocket’s impact, posing a new mystery for astronomers to unravel.

Why a double crater? While somewhat unusual – none of the Apollo S-IVBs that hit the Moon created double craters – they’re not impossible to create, especially if an object hits at a low angle. But that doesn’t seem to be the case here. Astronomer Bill Gray, who first discovered the object and predicted its lunar demise back in January, explains that the booster “came in at about 15 degrees from vertical. So that’s not the explanation for this one.”

Before and after photos at the location of the newly formed craters. Before image acquired 2022-02-28; after image acquired 2022-05-21. Credit: NASA/GSFC/Arizona State University.

The impact site consists of an 18-meter-wide eastern crater superimposed on a 16-meter-wide western crater. Mark Robinson, Principal Investigator of the LRO Camera team, proposes that this double crater formation might result from an object with distinct, large masses at each end.

“Typically a spent rocket has mass concentrated at the motor end; the rest of the rocket stage mainly consists of an empty fuel tank. Since the origin of the rocket body remains uncertain, the double nature of the crater may help to indicate its identity,” he said.

So what is it?

The Hubble space telescope has provided some of the most spectacular astronomical pictures ever taken. Some of them have even been used to confirm the value of another Hubble – the constant that determines the speed of expansion of the Universe. Now, in what Nobel laureate Adam Reiss calls Hubble’s “magnum opus,” scientists have released a series of spectacular spiral galaxies that have helped pinpoint that expansion constant – and it’s not what they expected.

The spectacular array of 36 galaxies in the lead image all have something in common. They host both a Cepheid variable and had a type Ia supernovae occur in them in the last 40 years. Combined, these two astronomical phenomena play a critical role in helping to determine how far away an object is and, consequently, how fast the Universe is expanding.

A Cepheid variable is a type of star that steadily pulsates with a very stable period and amplitude. What’s more, their luminosity is tied to their pulsating period, allowing scientists to have a direct tie between a Cepheid variable’s pulsating frequency, its luminosity, and, therefore, how far away it is. Hubble established distances to some Cepheid variables in the Andromeda Galaxy, which helped prove to the scientific community that the Milky way was only one of the billions of galaxies in the larger Universe.

UT’s own Paul Sutter explains how the Universe expands.
Credit – Paul M Sutter YouTube Channel

Type Ia supernovae are more temporary but spectacular events that result when two stars collide in a binary system. One of these stars – a white dwarf – limits the peak luminosity of the explosion, allowing scientists to measure that luminosity as it reaches us, which in turn can be used to calculate the event’s distance.

Both of these astronomical phenomena are critical steps on the “cosmic distance ladder” that helps scientists determine how far it is to a given object. As part of its decades-long observational campaign, Hubble has captured images of more than 36 galaxies that contain both a Cepheid variable and a Type Ia supernova, allowing them to correlate and check their data against other observations as well as the two methods themselves.

Three-dimensional models of astronomical objects can be ridiculously complex. They can range from black holes that light doesn’t even escape to the literal size of the universe and everything in between. But not every object has received the attention needed to develop a complete model of it, but we can officially add another highly complex model to our lists. Astronomers at the University of Arizona have developed a model of VY Canis Majoris, a red hypergiant that is quite possibly the largest star in the Milky Way. And they’re going to use that model to predict how it will die.

How red hypergiants die has been a matter of some debate recently. Initially, astronomers thought they simply exploded into a supernova, as so many other stars do. However, more recent data show a significant lack of supernovae compared to the numbers that would be expected if red hypergiants themselves we to explode that way.  

The going theory now is that they are more likely to collapse into a black hole, which is much harder to observe directly than the initially suggested supernovae. It remains unclear what precisely the characteristics of the stars that would evolve into black holes are, and to find out; it would be beneficial to have a model.

UT video discussing how big stars can get.

Enter the team from UA. They picked VY Canis Majoris as an excellent stand-in for the type of red hypergiants they were interested in learning more about. The star itself is massive, ranging from 10,000 AU to 15,000 AU in size, meaning it would reach 10,000 to 15,000 times farther out than the Earth is from the Sun today. And it is only 3,009 light-years away from Earth as it is. This makes VY Canis Majoris, which resides in the southern constellation Canis Major, fascinating to observers.  

Its sheer size and proximity to our solar system make it an excellent observational candidate. With good observational data, astronomers can see the breathtaking complexity of what the star’s surface actually looks like.