Astronomy Archives

January 28, 2010December 24, 2015 by Fraser Cain

Antarctica Pictures

Antarctica is one of the most remote places on Earth, and extremely difficult to visit. But there are many spacecraft constantly watching the southern continent, studying its climate and geography. Here are some amazing Antarctica pictures from space.

Here’s a picture of the entire continent of Antarctica seen from space. It was captured piece by piece by several spacecraft, and then stitched together into this amazing mosaic image.

This is a close up view of Victoria Land, in Antarctica. It’s a region of the continent that’s bounded by the Ross Sea, and it was discovered by James Clark Ross.

This is a photo of Don Juan Pond, a tiny, extremely salty lake in Antarctica. It has a greater salinity than the Dead Sea or Lake Assal. It’s estimated to be about 30 times saltier than the ocean. It’s the only lake in Antarctica that never freezes.

This is an image of the Bellingshausen Sea in Antarctica. It’s hard to see which parts of this image are over the ocean, and which parts are over the land.

This photograph shows the break up of the Larsen Ice Shelf in 2001.

We’ve written many articles about Antarctica for Universe Today. Here’s an article about an unusual micrometeorite found in Antarctica, and here’s an article about an extremophile hunt in Antarctica.

If you’d like more info on Antarctica, check out the LIMA Mosaic Images of Antarctica site, and here’s a nice photo of the entire continent.

We’ve recorded several episodes of Astronomy Cast about Earth. Listen here, Episode 51: Earth.

January 28, 2010December 24, 2015 by Fraser Cain

Amazon Rainforest Pictures

Here are Amazon forest pictures from space. Satellite observation of the Amazon is the best way to keep track on the ongoing deforestation of the region.

Here’s a cool picture that shows how the Amazon has a dry period too, where the skies have nice fluffy clouds. The Amazon River is up at the top of the image, with some of its other tributaries further down in the picture.

The next of our Amazon pictures was captured by NASA’s Terra satellite. It’s mostly untouched forest, but you can see regions of deforestation near the top center. The red dots in the image are fires, likely used to clear forested land.

This is a photograph of the Mato Grosso region of the Amazon forest. Officials in Brazil think that almost 50% of the deforestation in the Amazon in recent years occurred in this region.

Here’s a beautiful image of the Amazon captured by the crew of the space shuttle. You can see large clouds of smoke coming from deforestation activities in the region, as farmers clear land for cattle.

Here’s an image that shows the amount of deforestation going on in the Amazon rainforest. You can see the alternating strips of forest and clearcuts as farmers expand deeper into the forest.

We’ve written several episodes about the Amazon rainforest for Universe Today. Here’s an article about the world’s widest river, and here’s a story about how deforestation in Brazil is affecting the local climate.

If you’d like more info on the Amazon, check out this article on Amazon deforestation from NASA, and how the Amazon is very resilient to drought.

We’ve recorded several episodes of Astronomy Cast which are on this topic. Check out Episode 151: Atmospheres.

January 28, 2010December 24, 2015 by Jean Tate

Hypernova

Artist impression of the twin jets from a GRB. Credit: Dana Berry/SkyWorks Digital

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Nova, “new star”; supernova, a “super” nova; hypernova, a super-duper, or super super, nova!

This word appeared in the astronomical literature at least as early as 1982, and refers to a kind of core-collapse supernova far brighter (>100 times) than usual; its meaning has changed somewhat, and today generally refers to the core collapse of particularly massive stars (>100 sols), whether or not they are spectacularly brighter than other core-collapse supernovae (though they are that too).

Most times you’ll come across hypernovae in material on gamma ray bursts (GRBs), many of which seem to involve emission of electromagnetic radiation with total energy many times that from ordinary supernovae (whether core collapse or Type Ia). Long-duration GRBs have jets, presumably from the poles of the temporary accretion disk which forms around the new black hole at the heart of the collapsed core of the progenitor (short-duration GRBs, which also produce jets, are thought to be the merger of two neutron stars, or a neutron star and a stellar-mass black hole), but even when viewed side-on (i.e. not looking into one of the jets), these GRBs are intrinsically much brighter than other core collapse supernovae.

If a supernova were to occur a few hundred light-years from us, we’d certainly notice it, and there might be some impact on our atmosphere; if there was a hypernova the same distance away, we’d suffer (not only from the increased incidence of cancer due to the far greater intensity of cosmic rays, but also from changes in weather and climate, and damage to ecosystems); if the jet were aimed directly at us, we’d be toast (while those on the other side of the world would survive the few seconds-long blast, they’d die from the consequences).

Fortunately, it seems there are no stars likely to go hypernova on us … at least not within a few tens of thousands of light-years. Whew!

Have I whet your appetite for more? Check these sites out! Brighter than an Exploding Star, It’s a Hypernova! (NASA’s Imagine the Universe), Face on Beauty (Phil Plait), and Hypernova (Swinburne University).

Like everyone else, Universe Today writers love a good story about explosions … so there are quite a few on hypernovae! Some examples: Gamma Ray Bursts and Hypernovae Linked, ESO Watches Burst Afterglow for Five Weeks, and Carbon/Oxygen Stars Could Explode as Gamma Ray Bursts.

No surprise that Astronomy Cast episode Gamma-Ray Bursts features hypermovae! Back in 2007, after attending the American Astronomical Society meeting, Pamela learning something new about hypernovae; what? Well, check out the episode, What We Learned from the American Astronomical Society and find out for yourself!

References:
NASA
ESO

January 28, 2010December 24, 2015 by Jean Tate

Atomic Radius

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If you can imagine an atom, of an element, as a sphere, then the radius of that sphere would be the atomic radius of that element. However, as atoms are things far better described using quantum mechanics than classical physics, the definition – even the concept – of atomic radius is tricky (and, in fact, there are actually several different definitions!).

Start with the Bohr atomic model, and an atom of hydrogen. In this model, the atomic radius (Bohr radius) is related to the lowest energy level of the electron, and has an exact value which involves Planck’s constant, the fine structure constant, c (speed of light), and the mass of the electron ( h/(2πcαm_e) – approx 53 pm … that’s picometers, trillionths of a meter, in case you were wondering). Although the Bohr model of the atom is no longer used, except in teaching, the Bohr atom radius for hydrogen is a key physical constant.

If you have a crystal, of a salt, you can study it with x-rays, and work out how far apart the entities in the crystal lattice are; those entities are ions (not atoms), so the atomic radii estimated this way are called ionic radii. No surprise that the ionic radii of a particular element depend on the ionization state of the ions!

In a metal, one or more outer electrons become part of the sea of electrons throughout the metal, which give the metal its high electrical conductivity. The atomic radii of metal atoms in this environment are called metallic radii.

By now you should be able to guess what the covalent radius is (in molecules with covalent bonds, the atomic radii are estimated from the bond lengths), and what the Van der Waals radius is (if two atoms are not bound in a molecule, the minimum distance between them is determined by the Van der Waals force, and radii estimated this way are …).

Chemguide, a UK site, has a nice intro, Atomic and Ionic Radius; this Frostburg State University page is a bit more advanced ; and here is a list of the elements, sorted by atomic radius.

Astronomy Cast episodes relevant to this topic include Quantum Mechanics, Wave Particle Duality, and Inside the Atom.

January 28, 2010December 24, 2015 by Mike Simonsen

Long Anticipated Eruption of U Scorpii Has Begun

Artists rendition of the recurrent nova RS Oph Credit: David Hardy/PPARC

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Today, two amateur astronomers from Florida detected a rare outburst of the recurrent nova U Scorpii, which set in motion satellite observations by the Hubble Space Telescope, Swift and Spitzer. The last outburst of U Scorpii occurred in February of 1999. Observers around the planet will now be observing this remarkable system intensely for the next few months trying to unlock the mysteries of white dwarfs, interacting binaries, accretion and the progenitors of Type IA supernovae.

One of the remarkable things about this outburst is it was predicted in advance by Dr. Bradley Schaefer, Louisiana State University, so observers of the American Association of Variable Star Observers (AAVSO) have been closely monitoring the star since last February, waiting to detect the first signs of an eruption. This morning, AAVSO observers, Barbara Harris and Shawn Dvorak sent in notification of the outburst, sending astronomers scrambling to get ‘target of opportunity observations’ from satellites and continuous coverage from ground-based observatories. Time is a critical element, since U Sco is known to reach maximum light and start to fade again in one day.

There are only ten known recurrent novae (RNe). This, coupled with the fact that eruptions may occur only once every 10-100 years, makes observations of this rare phenomenon extremely interesting to astronomers. Recurrent novae are close binary stars where matter is accreting from the secondary star onto the surface of a white dwarf primary. Eventually this material accumulates enough to ignite a thermonuclear explosion that makes the nova eruption. ‘Classical novae’ are systems where only one such eruption has occurred in recorded history. They may indeed have recurrent eruptions, but these may occur thousands or millions of years apart. RNe have recurrence times of 10-100 years.

The difference is thought to be the mass of the white dwarf. The white dwarf must be close to the Chandrasekhar limit, 1.4 times the mass of the Sun. This higher mass makes for a higher surface gravity, which allows a relatively small amount of matter to reach the ignition point for a thermonuclear runaway. White dwarfs in RNe are thought to be roughly 1.2 times solar, or greater. The rate at which mass is accreted onto the white dwarf must be relatively high also. This is the only way to get enough material accumulated onto the white dwarf in such a short time, as compared to classical novae.

Recurrent novae are of particular interest to scientists because they may represent a stage in the evolution of close binary systems on their way to becoming Type IA supernovae. As mass builds up on the white dwarf they may eventually reach the tipping point, the Chandrasekhar limit. Once a white dwarf exceeds this mass it will collapse into a Type IA supernova.

A problem with this theory is the mass that is blown off the white dwarf in the erruption. If more mass is ejected during an eruption than has accreted during the previous interval between eruptions, the white dwarf will not be gaining mass and will not collapse into a Type IA supernovae. Therefore, scientists are eager to obtain all the data they can on these eruptions to determine what is happening with the white dwarf, the mass that is ejected and the rate of accretion.

AAVSO comparison sequence chart for U Sco

Observations from amateur astronomers are requested by the AAVSO. Data from backyard telescopes will be combined with data from mountaintop observatories and space telescopes to help unravel the secrets of these rare systems. AAVSO finder charts with comparison star sequences are available at: http://www.aavso.org/observing/charts/vsp/index.html?pickname=U%20Sco

January 27, 2010April 26, 2016 by Jean Tate

Main Sequence

Hertzsprung-Russell Diagram. Credit: ESO.

If you make a plot of the brightness of a few thousand stars near us, against their color (or surface temperature) – a Hertzsprung-Russell diagram – you’ll see that most of them are on a nearly straight, diagonal, line, going from faint and red to bright and blue. That line is the main sequence (of course, you must plot the absolute brightness – or luminosity – not the apparent brightness; do you know why?).

As you might have expected, the discovery of the main sequence had to wait until the distances to at least a few hundred stars could be reasonably well estimated (so their absolute magnitudes, or luminosities, could be worked out). This happened in the early years of the 20th century (fun fact: Russell’s discovery was how absolute luminosity was related to spectral class – OBAFGKM – rather than color).

So why, then, do most stars seem to lie on the main sequence? Why don’t we find stars all over the H-R diagram?

Back in the 19th century, it would have been impossible to answer these questions, because quantum theory hadn’t been invented then, and no one knew about nuclear fusion, or even what powered the Sun. By the 1930s, however, the main outlines of the answers became clear … stars on the main sequence are powered by hydrogen fusion, which takes place in their cores, and the main sequence is just a sequence of mass (faint red stars are the least massive – starting at around one-tenth that of the Sun – and bright blue ones the most – about 20 times). Stars are found elsewhere on the Hertzsprung Russell diagram, and their positions reflect what nuclear reactions are powering them, and where they are taking place (or not; white dwarfs are cinders, slowly cooling). So, broadly speaking, there are so many stars on the main sequence – compared to elsewhere in the H-R diagram – because stars spend much more of their lives burning hydrogen in their cores than they do producing energy in any other way!

It took many decades of research to work out the details of stellar evolution – what nuclear reactions for what mass and composition of a star, how the size of a star reflects its internal structure and composition, how some stars can live on long after they should be white dwarfs, etc, etc, etc – and there are still many unanswered questions today (maybe you can help solve them?).

The Main Sequence (University of Utah), Main Sequence Stars (University of Oregon), and Stars (NASA’s Imagine the Universe) are three good places to go to learn more.

Dating a Cluster – A New Trick, V is For Valentine… V838, and Capture A FUor! are just three of the many Universe Today stories which feature the main sequence.

Astronomy Cast covers the main sequence from the point of view of stellar evolution in The Life of the Sun and The Life of Other Stars; be sure to check them out.

References:
NASA
Hyperphysics

January 27, 2010December 24, 2015 by Nancy Atkinson

Supernova or GRB? Radio Observations Allow Astronomers to Find Unusual Object

Core-collapse supernova explosion expelling nearly-spherical debris shell. CREDIT: Bill Saxton, NRAO/AUI/NSF

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For the first time, astronomers have found a supernova explosion with properties similar to a gamma-ray burst, but without seeing any gamma rays from it. Radio observations with the Very Large Array (VLA) showed material expelled from supernova explosion SN2009bb at speeds approaching the speed of light. The superfast speeds in these rare blasts, astronomers say, are caused by an “engine” in the center of the supernova explosion that resembles a scaled-down version of a quasar. But astronomers don’t think this blast is one-of-a-kind, and say that more radio observations will point the way toward locating many more examples of these mysterious explosions.

“We think that radio observations will soon be a more powerful tool for finding this kind of supernova in the nearby Universe than gamma-ray satellites,” said Alicia Soderberg, of the Harvard-Smithsonian Center for Astrophysics.

Usually supernova explosions blasts the star’s material outward in a roughly-spherical pattern at speeds that, while fast, are only about 3 percent of the speed of light. In the supernovae that produce gamma-ray bursts, some, but not all, of the ejected material is accelerated to nearly the speed of light.

Engine-driven" supernova explosion with accretion disk and high-velocity jets. CREDIT: Bill Saxton, NRAO/AUI/NSF — Engine-driven

When the nuclear fusion reactions at the cores of very massive stars no longer can provide the energy needed to hold the core up against the weight of the rest of the star, the core collapses catastrophically into a superdense neutron star or black hole. The rest of the star’s material is blasted into space in a supernova explosion. For the past decade or so, astronomers have identified one particular type of such a “core-collapse supernova” as the cause of one kind of gamma-ray burst.

The superfast speeds in these rare blasts, astronomers say, are caused by an “engine” in the center of the supernova explosion that resembles a scaled-down version of a quasar. Material falling toward the core enters a swirling disk surrounding the new neutron star or black hole. This accretion disk produces jets of material boosted at tremendous speeds from the poles of the disk.

“This is the only way we know that a supernova explosion could accelerate material to such speeds,” Soderberg said.

Until now, no such “engine-driven” supernova had been found any way other than by detecting gamma rays emitted by it.

“Discovering such a supernova by observing its radio emission, rather than through gamma rays, is a breakthrough. With the new capabilities of the Expanded VLA coming soon, we believe we’ll find more in the future through radio observations than with gamma-ray satellites,” Soderberg said.

Why didn’t anyone see gamma rays from this explosion? “We know that the gamma-ray emission is beamed in such blasts, and this one may have been pointed away from Earth and thus not seen,” Soderberg said. In that case, finding such blasts through radio observations will allow scientists to discover a much larger percentage of them in the future.

“Another possibility,” Soderberg adds, “is that the gamma rays were ‘smothered’ as they tried to escape the star. This is perhaps the more exciting possibility since it implies that we can find and identify engine-driven supernovae that lack detectable gamma rays and thus go unseen by gamma-ray satellites.”

One important question the scientists hope to answer is just what causes the difference between the “ordinary” and the “engine-driven” core-collapse supernovae. “There must be some rare physical property that separates the stars that produce the ‘engine-driven’ blasts from their more-normal cousins,” Soderberg said. “We’d like to find out what that property is.”

One popular idea is that such stars have an unusually low concentration of elements heavier than hydrogen. However, Soderberg points out, that does not seem to be the case for this supernova.

This research will be published in January 28 issue of the journal Nature.

Source: NRAO

January 27, 2010December 24, 2015 by Mike Simonsen

Kepler Goes Fishing and Reels in Two KOI

Sizes and temperatures of Kepler discoveries compared to Earth and Jupiter

By now you’ve probably heard about the first results from the Kepler mission to find extrasolar planets. Five new exoplanet discoveries were announced recently at the American Astronomical Society meeting in Washington, D.C. Four of the five new planets are larger than Jupiter, about 1.4 times its radius, and they all have orbital periods around their host stars of 3-5 days. Kepler 4b, the oddball of that bunch is about the size of Neptune.

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All of them are close to their parent stars, so they have high surface temperatures, 1500-1800K or 2240-2780 degrees F. None of this is very surprising. We knew Kepler could detect extrasolar planet transits, and the first ones were liable to be fairly large and close in. These are the easiest to detect in the shortest amount of time.

What is even more interesting to me, is the discovery of two so-called Kepler Objects of Interest (KOI). What is so interesting about KOI?

First, they were discovered because when they disappear behind the parent star from our point of view the light from the system is dimmed dramatically. I mean a lot! Usually this phase is known as the secondary eclipse, and is much less noticeable than the primary eclipse of the star as the planet transits across the face of the star. The fact that the light was dimmed more by the disappearance of the KOI means they are blazing hot and emitting a lot of light on their own. Astronomers estimate the temperature for KOI-74b to be 12250K (21590F) and KOI-81b a blazing 13500K (23840F). The hottest known exoplanet to date is a mild 2300K (3700F) in comparison.

Both KOI are actually hotter than their host stars. KOI-74b companion star is an A1V type star with a surface temperature around 9400K. KOI-81b has a companion type B9-A0V, with a temperature of approximately 10000K.

KOI-74b and KOI-81b are not massive enough to be stars, with solar masses of 0.111 and 0.212 respectively. That’s just not massive enough to start nuclear burning in the core. Yet each object is far too hot to only be shining by heat absorbed from its companion star and then re-emitted into space. This may mean they have evolved from hot stars into their current state, and they are slowly cooling with time. The problem with that theory is, with host stars that are relatively young type A and B stars, there doesn’t appear to have been enough time for these to have evolved from massive, hot stars to the state they are in now.

So what are they? They are the first of what will undoubtedly be a host of newly discovered objects from the Kepler mission. We live in exciting times for astronomy. We are now going fishing with new flies in the tackle box, and we have no idea what other KOI we’ll pull out of the next round of data.

January 26, 2010April 13, 2022 by Ken Kremer

Path clear for STS 130 to attach Tranquility module

This NASA artists concept shows ISS configuration after shuttle Endeavour has delivered and attached Tranquility and Cupola on STS 130 flight. Credit: NASA

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Teams up in space and on the ground completed crucial tasks over the weekend to clear the path for attachment of the new Tranquility module to the International Space Station (ISS). Astronauts aboard the ISS removed the last obstacle blocking the path to dock Tranquility to the orbiting outpost. Meanwhile, technicians at Pad 39 A loaded Tranquility and the Cupola workstation into shuttle Endeavour’s cargo bay in preparation for the planned Feb 7 blast off of the STS 130 mission at 4:39 AM.

In a complex robotic operation, Astronauts Jeff Williams and TJ Creamer with help from Soichi Noguchi worked to expose the docking port on Node 1, also known as Unity, where Tranquility will be joined to the station. This side facing port was occupied by another component known as Pressurized Mating Adapter 3, or PMA 3, which had to be removed in order to make way for connecting Tranquility.

During a several hour long operation, the astronauts deftly snatched the PMA-3 with the stations Canadian- built robotic arm, unlatched the hooks and then relocated PMA-3 to the zenith berthing port of the Harmony module, also known as Node 2, and locked it back into place. Leak checks confirmed a successful outcome. Node 2 is where space shuttle Endeavour will dock at the station at another docking port dubbed PMA-2.

NASA Artist's concept shows PMA 3 after relocation from Node 1 to Node 2 zenith (space facing) port. Endeavour will dock at Node 2 at blue colored docking port dubbed PMA 2. European Columbus module docked at left; Japanese Kibo module docked at right side of Node 2. Credit: NASA

The PMA’s are basically tunnels though which astronauts move to get about from the shuttle to the station or between adjacent modules on the station. After Endeavour departs, the ISS crew will again relocate PMA-2, this time from Harmony on to the far end port of Tranquility. The station is outfitted with three PMA’s altogether.

The teams at pad 39 A at the Kennedy Space Center (KSC) sealed the two payload bay doors for flight after installing and securing the Tranquility and Cupola modules, which are the primary payloads for the STS 130. Tranquility will house many of the ISS life support systems.

Endeavour's payload bay doors have been closed for launch after secured Tranquility node and 7 windowed Cupola work station. Cupola will provide a spectacular view of Earth and other celestial objects. Credit: NASA/Kim Shiflett

Today (Jan 26), KSC technicians also began final ordnance connections at the pad and carefully checked out the astronaut’s spacesuits before packing them into special containers to be loaded onto the shuttle.

Meanwhile work continues at NASA’s Marshall Spaceflight Center in Huntsville, Ala to assemble the four new ammonia coolant hoses essential for mission success. New hoses had to be constructed after two of the original 14 ft long hoses failed during pressure testing. The new lines were built by joining together shorter spare hoses already approved for flight and use aboard the ISS. A NASA spokesperson told me that “The original hoses were redesigned after the test failure and are on schedule for availability as a backup”.

The NASA press spokesman told me that the original subcontractor for the hoses has left the spaceflight business and therefore had to be replaced by a new subcontractor who is relatively new to the space business. The new hoses are due to arrive at the Kennedy Space Center in the next few days for installation aboard Endeavour.

The senior NASA shuttle management team meets on Wednesday (Jan. 27) at KSC for the official Flight Readiness Review (FRR) to assess in depth all aspects of the mission including launch, spacecraft and cargo and will then announce the official launch date. Flow processing is proceeding well at this time and no major issues are being worked.

I will be reporting on site from the Kennedy Space Center in February and directly from the launch pads for both STS 130 and SDO. Earlier STS 130 article by Ken Kremer

Endeavour aiming for on time launch with coolant hose fix ahead of schedule

STS 130 flight pressing forward to launch as NASA resolves coolant hose leak

STS-130 Shuttle flight facing delay due to Payload technical glitch

Shuttle Endeavour Rolled to Pad; Countdown to the Final Five Begins

Tranquility Module Formally Handed over to NASA from ESA

January 26, 2010December 24, 2015 by Jean Tate

Debunking Astrology: Mars Can’t Influence You

So you think the position of Mars in the sky at the time of your birth made you tall, dark, and handsome (or short, fair, and ugly)? Or lucky (or unlucky) in love? If you think believing in astrology is anywhere close to scientific, well, Dude, time to think again.

Pick two babies born within a minute of each other. One has two nurses and a doctor attending; the other, just a midwife. One is born in a brightly lit maternity ward in a downtown big city hospital; the other in a poorly lit room in a village 50 kilometers from the nearest big city. ‘Downtown’ is just a few meters above sea level; the village is situated on a 1000 meter high plateau. These local differences have far greater effects on the babies than Mars does. Let’s see how.

Nearly five centuries of physics have given us quite a few certainties, and among those are that the only long range forces in the universe are gravity and electromagnetism. And both of these, from Mars, are totally – and I mean totally – overwhelmed by those same forces that were produced by things near you when you were delivered. In a word, Mars can’t influence you.

Start with gravitation.

The gravitational force between you and Mars is greatest when Mars is closest to the Earth; let’s say that’s 56 million kilometers. Now Mars has a mass of 6.4 x 10²³ kg, so the acceleration, here on Earth, due to Martian gravity would be 1.4 x 10^-8 meters per second per second (m s^-2).

How did I work that out? By using Newton’s law of universal gravitation:
F = Gm₁m₂/r²
and:
F = ma
so:
a = Gm_Mars/distance-to-Mars².

How does this compare with variations in gravitational force due to adults standing nearby (everyone has a mother, so we won’t count her)?

Let’s take 60 kg as an adult’s mass, and a distance of 1 meter; that gives a gravitational acceleration of 4 x 10^-9 m s^-2, so just three adults nearby would have the same gravitational effect on you as Mars!

How does this compare with variations in gravitational force we know people born at the same time – but elsewhere on Earth – experienced?

Let’s take a difference in altitude of 1000 m (lots of big cities have altitudes greater than this – Mexico City, for example, is at 2240 m – and lots are close to sea level), and calculate the difference in acceleration due to the Earth’s gravity (this ignores several important factors, such as the Earth’s rotation, and local differences in g). Well, it works out as 0.003 m s^-2, or about 200,000 times greater than Martian gravity!

In fact, if you were born just half a centimeter higher, you’d be influenced to the same extent, gravitationally, as by Mars!

Next, electromagnetism.

You can be influenced, electromagnetically, in four separate ways: by a magnetic field, by an electric current, by an electric field, and by electromagnetic radiation. How powerful is Mars, electromagnetically?

There’s no electric current between Mars and Earth; the solar wind – which blows outward from the Sun (so Mars is ‘downstream’, and any electromagnetic influence carried by the solar wind would be from Earth to Mars) – is neutral, on balance, and carries no current.

The solar wind is a plasma, and any electric field there is in it will not be felt much more than a few Debye lengths’ away (basically, because electrons and ions are free to move in a plasma, they screen charges – the source of electric fields – quite effectively; the Debye length is about as far as an electric field can penetrate). Now the solar wind can be quite dynamic – meaning it can change a lot – but the Debye length in any part of it will rarely, if ever, be greater than a few tens of meters. Let’s be generous and say an electric field could be felt up to a kilometer away. But Mars never comes closer to the Earth than ~50 million km!

Well, that makes any electric field influence from Mars impossible, doesn’t it?!

While Mars does have a weak magnetic field, it has no influence on Earth, because the Earth’s own field creates a magnetosphere around us, one that screens out external magnetic fields. Besides, as Mars is downstream from us (the way the solar wind blows), and as the solar wind can carry (actually stretch) a magnetosphere only in the direction it blows, any magnetic influence would be from Earth to Mars, not Mars to Earth.

Three down, one to go.

The Earth’s atmosphere blocks all electromagnetic radiation except for that which we see by (and a bit on the UV side too), some infrared, and in the microwave and radio regions of the electromagnetic spectrum.

Mars is a very weak source of microwaves and radio waves, and even in the (radio) quietest places on Earth, electromagnetic radiation from (distant) radio stations, (distant) cellphone towers, TV satellites, airplanes overhead, etc totally, totally drowns out any Martian signals.

On a clear, moonless night, Mars may seem bright to your dark-adjusted eyes … but most likely you were born under quite bright lights, and indoors. No Martian influence here either.

So what do we have then?

Like I said, Mars can’t make you tall dark and handsome, nor can it influence your love life.