How does the mind work? What is reality? Self-professed wonder junkie Jason Silva has a new video, which debuted this weekend at the South by Southwest (SXSW) festival. Hit ‘play’ and get ready for a fast ride!
The first of three bright comets anticipated in 2013 became visible to North American observers this past weekend. Comet C/2011 L4 PanSTARRS is now currently visible low to the southwest at dusk, if you know exactly where to look for it.
Observers in the southern hemisphere have been enjoying this comet for the past few weeks as it reached naked eye visibility above 6th magnitude around late February and began its long trek northward. Comet PanSTARRS is on a 106,000+ year orbit with a high inclination of 84.2° with respect to the ecliptic. This also means that PanSTARRS is currently moving roughly parallel to the “0 Hour” line in Right Ascension (The same point occupied by the Sun during next week’s Vernal Equinox on March 20th) and is only slowly gaining elevation on successive evenings.
Observers in Hawaii and Mexico picked up PanSTARRS late last week, and scattered reports of sightings from the southern continental United States started trickling in Saturday night on the evening of March 9th. We managed to grab Comet PanSTARRS low to the southwest on Sunday evening on March 10th, about 30 minutes after local sunset.
We were surprised by the star-like appearance of the coma, about +1st to 2nd magnitude with a tiny fan-shaped tail. The comet was visible in binoculars only (I used our trusty pair of Canon 15×45 Image-Stabilized binocs for the task) and I couldn’t yet pick out the comet with the naked eye.
Several sightings westward followed. Clay Davis based in Santa Fe, New Mexico noted a visual magnitude of -0.5, saying that PanSTARRS was “Brighter than Mars” at magnitude +1 but “A challenge to keep in view.” Note that observer estimations of the brightness of comets can vary based on local sky conditions. Also, unlike a pinpoint star, the brightness of comets extends over its visible surface area, much like a faint nebula. The first sightings of the comet for many observers has been contingent on the weather, which can trend towards overcast for much of North America in early March. From our +28.5° northern latitude vantage point here just north of Tampa Bay Florida we had about a 10 minute window from when the sky was dark enough to spy PanSTARRS before it set below the local horizon.
Here are a few more images from Universe Today readers:
To see the comet we suggest;
A clear uncluttered southwestern horizon;
A reasonably clear sky;
Binoculars.
First naked eye sightings of the comet for U.S. and European latitudes should be forthcoming over the next few evenings. PanSTARRS just passed perihelion yesterday on March 10th at 0.3 Astronomical Units from the Sun (or 46.5 million kilometres, just inside the orbit of Mercury).
And Comet PanSTARRS may put on its best show over the next few nights. The Moon reaches New phase today at 3:51PM EDT/ 19:51 UT and starts lunation number 1116. On the next few evenings, the slim crescent Moon will slide by Comet PanSTARRS. Look for the 2% illuminated Moon 5° to the lower right of the comet on the evening of Tuesday March 12th. On the next evening, the 5% illuminated Moon will be 9° above Comet PanSTARRS on Wednesday, March 13th. The age of the Moon will be 28 hours old on Tuesday evening and 52 hours on Wednesday the 13th respectively, an easy catch. The Moonwatch website is a great place to check for those early lunar crescent sighting possibilities worldwide. Note that Comet PanSTARRS also passes less than 30’ from the planet Uranus (about the diameter of the Full Moon) on the evening of the 12th at 8 PM EDT/24UT. +6th magnitude Uranus may just be visible near the head of the comet using binoculars or a small telescope. Keep in mind, they just appear to be close as seen from our Earthly vantage point. PanSTARRS is currently 1.1 A.U.s from the Earth, while Uranus is on the other side of the solar system at 21 A.U.s distant!
PanSTARRS also crosses the Celestial Equator today on March 11th and the Ecliptic on March 13th. Observers from dark sky sites may get the added bonus of the zodiacal light, a true photographic opportunity!
Spacecraft studying the Sun are also giving us views of Comet PanSTARRS from a different perspective. NASA’s twin STEREO A & B spacecraft are positioned to monitor the Sun from different vantage points along the Earth’s orbit. Often, they see comets as an added bonus. Comet PanSTARRS has just moved into the field of view of STEREO-B’s Heliospheric Imager and has given us amazing views of the comet and the Earth in the distance over the past week.
From STEREO, the remarkable fan-shaped dust tail of PanSTARRS stands out in profile. The dust tail of a comet always points away from the Sun. Driven by the solar wind, a comet’s tail is actually in front of it as it heads back out of the solar system! An ultimate animation of Comet PanSTARRS just came to our attention today via @SungrazerComets on Twitter;
As of this writing, PanSTARRS seems to be performing as per predictions with an observed magnitude of around +1. The comet will continue on its northward trek, becoming a circumpolar object for observers based around latitude 50° north on April 2nd. Comet PanSTARRS should dip back below +6th magnitude around April 15th.
But this is but Act One in a forecasted three act cometary saga for 2013. Comet C/2012 F6 Lemmon will grace early dawn skies in April for northern hemisphere observers, and then all eyes will be on Comet C/2012 S1 ISON for the hoped for grand finale later this year. Interestingly, ESA’s Solar Heliospheric Observatory will get a look at this sungrazing comet as it passes through its LASCO C3 camera’s field of view. Clear skies, and may 2013 go down as the Year of the Comet!
-Check out photos of Comet PanSTARRS and more being added daily to the Universe Today’s Flickr gallery.
Cats, celebrities and fictional creatures all have a home in the asteroid belt. That’s because the people that found these asteroids often have the privilege of naming the minor planets after anything they want — with a few guidelines, of course.
So what are the rules? According to the International Astronomical Union’s Minor Planet Center, all “minor planets” should adhere to the following guidelines:
– 16 characters long, or less;
– One word, if possible;
– Pronounceable, non-offensive and not too similar to names of other minor planets or natural planetary satellites;
– If named after a military/political persona, 100 years must have passed since the person died or the event occurred;
– No commercial names;
– Names of pets are strongly discouraged. (More on that later.)
Below are some of the more whimsical names of asteroids. What’s awesome about them is how willing the discoverer was to show his or her light side on what must have been a solemn occasion for them.
9) James Bond (9007): This actually isn’t too surprising, since Bond has been to space a few times, most notably attempting “re-entry” during the film Moonraker. Still, it’s a fair stretch from flying the space shuttle to navigating the asteroid belt.
8) Odysseus (1143): This ever-patient sailor probably would have been unhappy with a trip into space in addition to seeing his friends die in war, fighting with the Cyclops and getting stranded far from home.
7) Beowulf (38086): Named after the hero in an Old English epic poem. He’ll be handy in case we come across any Grendel-like creatures in outer space.
6) Tomhanks (12818) and (5) Megryan (8353): Cue the “sleepless in space” jokes, which accelerated in other media when the two asteroids came within 40 million miles of each other in 2011 (relatively close for asteroids.) That said, Tom Hanks is a well-known advocate of the space program. He starred in Apollo 13, was prominent behind the scenes in HBO’s From the Earth to the Moon miniseries and is a friend of astronauts.
4) Apophis (99942): This asteroid has come under a lot of scrutiny because for a while, astronomers weren’t clear on if it would hit the Earth. But we know now it is definitely not a threat. The asteroid is actually named after a nemesis character in the sci-fi series Stargate SG-1.
3) Monty Python (13681): The famed British comedy troupe now has a permanent monument to their silly walks and elderberry insults in space. Not only that, but each of the members of the group has an asteroid named after him.
2) Mr. Spock (2309): This asteroid was not named after the famous Star Trek character, but after the cat of discoverer James B. Gibson. The feline, like its namesake, was also “imperturbable, logical, intelligent, and had pointed ears,” according to a notice published in September 1985 in the Minor Planet Center.
1) Jabberwock (7470): In the ultimate expression of gyring and gimbling in the wabe, Lewis Carroll’s famous Jabberwocky poem has a namesake. We just hope it didn’t inherit the jaws and claws.
We also wanted to mention another named asteroid, even though we don’t think it has a weird name at all: Asteroid 158092 Frasercain, named after our esteemed publisher of Universe Today. This asteroid was officially designated on August 21, 2008. You can read about it here.
Also, while looking for silly asteroid names, we stumbled across one that is quite meaningful and perhaps the most appropriate space name ever.
45 Eugenia has a moon called Petit-Prince, honoring Antoine de Saint-Exupéry’s The Little Prince. The children’s book follows the exploit of a boy who lived on an asteroid and explored other asteroids, as well as Earth.
Before a man could head into space, the Russians felt a mannequin needed to get there first.
It was on this day (March 9) in 1961 that Ivan Ivanovich — the mannequin, or space dummy — made his first flight in a Sputnik. He then took another turn in space later that month before being placed into storage for decades. United States businessman (and failed presidential candidate) Ross Perot bought him at auction in the 1990s, and lent him to the Smithsonian National Air and Space Museum. He’s on display there today.
Universe Today caught up with Cathleen Lewis, the museum’s curator of international space programs and spacesuits in the division of space history. She explained that the mannequin was actually designed and built by three organizations:
– Zvezda (aka JSC Zvezda and RD&PE Zvezda), a firm known for high-altitude suits and spacesuits;
– The Institute for Bio-Medical Problems, which performed aerospace medicine research;
– The Moscow Institute for Prosthetics, which built the mannequin using specifications from the first two groups.
Here are some of the lessons the Russians learned from Ivan Ivanovich’s flight, according to Lewis:
– What the environment is like inside the spacecraft. While the Soviets had already sent dogs and other animals into space in that time, Lewis said they were sent up in their own self-contained canisters. The chest cavity of Ivan included accelerator and angular rate changes to see what gravity changes he was experiencing. He also measured the level of radiation. Notably, Ivan actually went up twice before the first man in space (Yuri Gagarin), but the reasons are still unclear. “One assumes that because they did do it twice, they weren’t satisfied with the result the first time,” Lewis said. “But there were not a lot of modifications [between flights], so it might have been a testing failure or ambiguity in the results.”
– The communications network. During the early years of the space program, the Americans had a number of ground and ship stations scattered around the world. These stations allowed constant, but not completely continuous, contact with the astronauts. The Soviets had a much smaller network, and wanted to know exactly when the cosmonauts would be audible to ground control. The solution? Recorded singing. “They were broadcasting a song, a folk song from the spacecraft,” she said. The song had an unintended consequence: those listening in from other countries thought there was an actual cosmonaut on board, leading to rumors that other cosmonauts died before Gagarin’s flight, she said.
– Limited public outreach. In the closed Soviet society of the time, public broadcasts of missions generally happened after the fact. Engineers had to figure out how not to alarm the locals if Ivanovich ended up falling nearby a populated area and officials could not retrieve him first. They therefore wrote the word “mannequin” on Ivan to make sure people understood what was going on. It turned out the precaution was never needed, though. “He was more on target than Gagarin,” Lewis said.
Imagine visiting Star Fleet headquarters in the 23nd Century and being engulfed by a holodeck journey to a 21st century NASA Space Shuttle; complete with a full sized Hubble Space Telescope – perhaps the important science instrument ever constructed and an outstanding legacy of the Space Shuttle Program.
Well that’s the thrilling new experience awaiting the visiting public and space enthusiasts alike starting this summer at the Kennedy Space Center Visitor Complex (KSCVC) in Florida – after the ghostlike Space Shuttle Atlantis (see photo album above & below) is unveiled from a thick coating of shrink wrapped plastic.
But – there is one important caveat regarding the holodeck dream sequence.
Starting on June 29 you will be seeing the ‘real deal’, an actual space flown NASA Space Shuttle Orbiter – not a high tech imaginary glimpse, engineering reproduction or holodeck recreation.
During the recent SpaceXCRS-2 launch events, I was very fortunate to take a behind the scenes inspection tour all around of the new ‘Space Shuttle Atlantis’ pavilion that’s been under construction at the Kennedy Visitor Complex for a year and is now racing towards completion.
And Atlantis is still supremely impressive beneath that white plastic wrap – unlike any shuttle view I’ve see over the years.
Scan through my photo album walking around Atlantis – covered in 16,000 square feet of shrink wrap plastic – and the Star Fleet like pavilion that truly reminded me of an exciting Star Trek adventure ; to see what’s in store soon. The orange exterior pavilion facade is meant to evoke the scorching heat of reentry into the Earth’s atmosphere.
The plastic wrap is protecting the orbiter from construction debris and will be unfurled in May. Then the payload bay doors will be carefully opened and the Canadian built remote manipulator system (RMS) — or robotic arm — will be installed and extended.
Inside her new 90,000-square-foot home, everyone will be treated to breathtaking, up close views of the real ‘Space Shuttle Atlantis’ mounted high on steel pedestals – tilted at exactly 43.21 degrees – simulating the outlook as though she was ‘in flight’ orbiting Earth and approaching the International Space Station (ISS).
The ISS and Hubble are the primary legacies of the Space Shuttle program. Atlantis flew 33 total space missions, spent 307 days in orbit and conducted the final flight of the shuttle era.
You’ll gaze from stem to stern and from above and below – and all while peering down into the humongous open cargo bay, up to the heat shield tiles, or across to the engines, wings, tail and crew flight deck. Walkways will provide exquisite up close viewing access.
Atlantis rises some 30 feet off the ground. Although her nose soars 26.5 feet above ground the portside wingtip sits only 7.5 feet from the floor. The wing tip top soars 87 feet from the ground.
And sitting right beside Atlantis will be a co-orbiting, high fidelity full scale replica of NASA’s Hubble Space Telescope which was deployed and upgraded by the astronaut crews of six space shuttle missions.
ISS module mockups, simulators and displays will tell the story of the massive stations intricate assembly by several dozen shuttle crews.
More than 60 exhibits, hands- on activities and artifacts surrounding Atlantis will tell the complete story of the three-decade long Space Shuttle program and the thousands of shuttle workers who prepared all five orbiters for a total of 135 space missions spanning from 1981 to 2011.
Atlantis has been lovingly preserved exactly as she returned upon touchdown at the shuttle landing strip at the conclusion of her last space mission, STS-135, in July 2011 – dings, dents, scorch marks, you name it. And that is exactly as it should be in my opinion too.
Shuttle Atlantis was towed to the Visitor Complex in November. The orbiter is housed inside a spanking new six- story museum facility constructed at a cost of $100 million that dominates the skyline at the largely revamped Kennedy Space Center Visitor Complex.
Standing tall right outside the entry to the museum pavilion, visitors will see full scale replicas of the twin solid rocket boosters mated to the orange external fuel tank, suspended 24 feet above ground – and reaching to a top height of 185 feet. They will be erected vertically, precisely as they were at the Shuttle Launch Pads 39 A and 39 B. It will give a realistic sense of what it looked like atop the actual shuttle launch complex.
The mighty steel framework for holding the boosters in place (in case of hurricane force winds up to 140 MPH) was coming together piece by piece as workers maneuvered heavy duty cranes before my eyes during my pavilion museum tour just days ago.
Well, get set to zoom to space as never before beginning on June 29 with the last shuttle orbiter that ever flew in space.
According to Analytical Graphics, Inc. (AGI), the Center for Space Standards and Innovation (CSSI) has determined that on January 22, 2013 debris from the Chinese FENGYUN 1C collided with Russia’s BLITS satellite. The FENGYUAN 1C is the satellite that was destroyed by China on January 11, 2007 in a test of an anti-satellite missile. The collision changed the orbit of the Russian satellite, along with its spin velocity and attitude. The animation above is from AGI and it depicts the event. Continue reading “Chinese Space Debris Collides with Russian Satellite”
We’ve all been there. Well OK, all public star party telescope operators have been there. You’re set up and you’ve got a stunning view of Saturn centered in the field of view. But then the first member of the viewing public takes a quick glance and steps back from the eyepiece, stating “yeah, I saw that through the last four ‘scopes…”
What do you do when every telescope down the row is aimed at the same object? Or worse yet, what do you aim at when there is no Moon or bright planets above the horizon? Every seasoned telescope operator has a quick repertoire of secret favorites, little known but sure-fire crowd pleasers. Sure, Saturn is awesome and you should see it through a telescope… but it’s a big universe out there.
I’ve even seen clubs assign objects to individual telescopes to avoid having everyone point at the same thing, but this method is, well, boring for the scope operators themselves. Most backyard astronomers can simply look at a tube pointed at Orion and know the neighboring telescope is aimed at the Orion Nebula. What follows is our very own highly subjective (but tested in the field!) list of secret star party faves. Yes, it is mid-northern latitude-centric. It also covers a span of objects of all types, as well as a handy information chart of where in the sky to find ‘em and a few surprises. We also realize that many public star parties often take place downtown under light polluted skies, so a majority of these are brighter objects. Don’t see your favorite? Drop us a line and let us know!
12. The Double Cluster: Straddling the border of the constellations Perseus and Cassiopeia, this pair of clusters is a fine sight at low power. The technical designation of the pair is NGC 884 and NGC 869 respectively and the clusters sit about 7000 light years distant. You can just see the pair with the naked eye under suburban skies.
11. Herschel 3945: A popular summer-to-fall star party target is the colored double star Albireo is the constellation Cygnus. But did you know there’s a similar target visible early in the year as well? I call Herschel 3945 the “winter Albireo” for just this reason. This 27” split pair of sapphire and orange stars offers a great contrast sure to bring out the “ohs” and “ahs.” Continue reading “12 Star Party Secret Weapons”
This is the big week so many of us in the northern hemisphere have been waiting for. Comet C/2011 L4 PANSTARRS, which has put on a splendid show in the southern hemisphere, now finally comes to a sky near us northerners!
Sky watchers in Australia and southern South America report it looks like a fuzzy star a little brighter than those in the Big Dipper with a short stub of a tail visible to the naked eye. The comet should brighten further as it wings its way sunward. Closest approach to the sun happens on March 10 at a distance of 28 million miles. That’s about 8 million miles closer than the orbit of Mercury.
Though very low in the western sky after sundown, the comet should be visible across much of the U.S., southern Canada and Europe beginning tonight March 8.
PANSTARRS’ low altitude presents a few challenges. Approaching clouds, general haziness and the extra thickness of the atmosphere near the horizon absorbs the comet’s light, causing it to appear fainter than you’d expect. A casual sky watcher may not even notice its presence. That’s why I recommend bringing along a pair of binoculars and using the map that best fits your latitude. Find a place with a wide open view to the west, focus your binoculars on the most distant object you can find (clouds are ideal) and then slowly sweep back and forth across the sky low above the western horizon
As the nights pass, PANSTARRS rises higher in the sky and becomes easier to spot for northern hemisphere observers while disappearing from view in the south. On the 12th, a thin lunar crescent will shine just to the right of the comet. Not only will it make finding this fuzzy visitor easy-peasy, but you’ll have the opportunity to make a beautiful photograph.
The maps shows the arc of the comet across the western sky in the coming two weeks for three different latitudes. Along the bottom of each map is the comet’s altitude in degrees for the four labeled dates. The sun, which is below the horizon, but whose bright glow you’ll see above its setting point, will help you determine exactly in what direction to look.
A word about altitude. Astronomers measure it in degrees. One degree is the width of your little finger held at arm’s length against the sky. Believe it or not, this covers two full moon’s worth of sky. Three fingers at arm’s length equals 5 degrees or the separation between the two stars at the end of the bowl of the Big Dipper. A fist is 10 degrees. This weekend PANSTARRS will be 2-3 “fingers” high around 25 minutes after sunset when the sky is dark enough to go for it.
To find PANSTARRS, locate it on the map for a particular date, note its approximate altitude and relation to where the sun set and look in that direction. Assuming your sky to the west is wide open and clear, you should see a comet staring back. If you don’t find it one night, don’t give up. Go out the next clear night and try again. While Comet PANSTARRS will fade over the next few weeks, it will also rise higher into a darker sky and become – for a time – easier to see. I also encourage you to take out your telescope for a look. You’ll see more color in the comet’s head, details in its tail and an intensely bright nucleus (center of the comet), a sign of how fiercely sunlight and solar heating are beating up on this tender object.
Earth. It seems so solid and permanent. But really, all you need to do is expand the Sun enough, and the entire planet would melt away. Or worse, find yourself at the mercy of some seriously powerful and angry aliens.
Actually, the beings who destroy Earth in The Hitchhiker’s Guide to the Galaxy, which first aired on BBC Radio 4 on this day (March 8) in 1978, were not so much angry as logical about their reasons.
In the novel, Earthlings are shocked when extraterrestrial beings — known as the Vogons — arrive with plans to build a hyperspatial express route that runs through Earth’s orbit. The plans for the route were apparently lodged in Alpha Centauri (a star system four light-years away) for the past 50 Earth years, leaving residents of the planet “plenty of time to lodge any formal complaint.”
The Vogons then prepare to do the deed. The book Douglas Adams wrote describes it thusly:
“Energize the demolition beams.” Light poured out of the hatchways … There was a terrible ghastly silence. There was a terrible ghastly noise. There was a terrible ghastly science. The Vogon Constructor Fleet coasted away into the inky starry void.
The situation had us at Universe Today wondering: just how did the Vogons do it? There isn’t much to go on, admittedly; a demolition beam, and then a terrific noise as the planet breaks apart.
We scoured the Internet for some answers and came up with these ideas:
Anti matter
What matter and antimatter might look like annihilating one another. Credit: NASA/CXC/M. Weiss
Anti matter is most simply, the opposite of matter. If you think of matter as being made up of electrons, neutrons and protons, anti matter has its own particles that have the opposite charge and magnetic moment (a property of magnetism.) You can read more technical details of anti matter in our past story, but here’s the important take-away: when matter and anti matter collide, they kill each other dead and produce gamma rays or other fundamental particles in the process. Phil Plait (author of the blog Bad Astronomy, now at Slate) says it’s indeed possible to blow up the Earth with it, but it would take a trillion tons. That’s not only complicated, but expensive. “Given that it currently costs hundreds of billions of dollars to make a single ounce of anti matter, you might have to work an extra job to cover the expense,” he wrote on Blastr.
Black hole
If a black hole were to pop up right next to Earth or inside the planet, this might be a way to shrink the planet down to nothing super-quick. We’re not sure how the Vogons did this, but hey, we’re talking science fiction here. It’s also unclear to us how bright this would look (remember, the Vogons had a light beam), but maybe the Vogons turned on the lights for dramatic effect. And here we should interject with some sobering reality from NASA, too: “Black holes do not go around in space eating stars, moons and planets,” the agency once wrote, adding that even if a black hole appeared where the Sun is today, Earth still wouldn’t be sucked over there. In fact, the gravitational force would be identical and the planets would continue their merry orbits.
A Death Star
Yes yes, we know, we’re mixing up our science fiction franchises. This was actually a laser-blasting, planet-destroying machine from Star Wars. But at risk of offending the Internet, a couple of legitimate points: There’s nothing to stop alien civilizations from sharing technology, or perhaps acquiring it, rather than spend the money to develop it themselves. In 2011, three researchers from the University of Leicester suggested that indeed a Death Star could destroy a planet, given an adequate power source. Check out the details in our past Universe Today story.
Do you have some other ideas of how the Vogons destroyed Earth?
Due to a fast approaching solar storm, NASA has temporarily shut down surface operations of the Curiosity Mars Science Lab (MSL) rover.
NASA took the precautionary measure because ‘a big coronal mass ejection’ was predicted to hit Mars over the next few days starting March 7, or Martian Sol 207 of the mission, researchers said.
The rover team wants to avoid a repeat of the computer memory glitch that afflicted Curiosity last week, and caused the rover to enter a protective ‘safe mode’.
“The rover was commanded to go to sleep,” says science team member Ken Herkenhoff of the US Geological Survey (USGS).
“Space weather can by nasty!”
This is the 2nd shutdown of the 1 ton robot in a week. Curiosity had just been returned to active status over the weekend.
A full resumption of science operations had been anticipated for next week, but is now on hold pending the outcome of effects from the solar storm explosions.
“We are making good progress in the recovery,” said Mars Science Laboratory Project Manager Richard Cook, of NASA’s Jet Propulsion Laboratory, prior to the new solar flare.
“Storm’s a-comin’! There’s a solar storm heading for Mars. I’m going back to sleep to weather it out,” tweeted Curiosity.
Solar flares cause intense bursts of radiation that can damage spacecraft and also harm space faring astronauts, and require the installation of radiation shielding and hardening on space based assets.
Since Mars lacks a magnetic field, the surface is virtually unprotected from constant bombardment by radiation.
NASA’s other spacecraft exploring Mars were unaffected by the solar eruptions – including the long lived Opportunity rover and the orbiters; Mars Odyssey & Mars Reconnaissance Orbiter.
Eventually, the six-wheeled mega rover will set off on a nearly year long trek to her main destination – the sedimentary layers of the lower reaches of the 3 mile (5 km) high mountain named Mount Sharp – some 6 miles (10 km) away.
So far Curiosity has snapped over 48,000 images and traveled nearly 0.5 miles.
Curiosity’s goal is to assess whether the Gale Crater area on Mars ever offered a habitable zone conducive for Martian microbial life, past or present.