Stories tagged mars

Sep
25
2007

Skylights to possible Mars caves

NASA's Mars Odyssey spacecraft has discovered entrances to seven possible caves on the slopes of a Martian volcano.

Hot spots

Mars "caves": Image credit: NASA/JPL-Caltech/ASU/USGS
Mars "caves": Image credit: NASA/JPL-Caltech/ASU/USGS
Using infrared imaging, the holes showed up as bright "hot spots" in photos taken during the cold of night (see right hand photo). In daytime shots they were colder than their surroundings (middle photo). The left photo uses the visable spectrum. This possible cave skylight informally called "Annie," has a diameter about double the length of a football field.

Seven Sisters

Seven Sisters
Seven Sisters
The discovered holes, dubbed "Seven Sisters," are at some of the highest altitudes on the planet, on a volcano named Arsia Mons near Mars' tallest mountain.

What are they?

A report of the discovery of the possible cave skylights by Cushing and his co-authors was published online recently by the journal Geophysical Research Letters.

The new report proposes that the deep holes on Arsia Mons probably formed as underground stresses around the volcano caused spreading and faults that opened spaces beneath the surface. Some of the holes are in line with strings of bowl-shaped pits where surface material has apparently collapsed to fill the gap created by a linear fault. NASA.gov.

Sep
13
2007

The Orion crew exploration vehicle: This rendering represents a concept of the Orion crew exploration vehicle. NASA's Constellation Program is getting to work on new spacecraft that will return humans to the moon and blaze a trail to Mars and beyond.  Image courtesy:Lockheed Martin Corp.
The Orion crew exploration vehicle: This rendering represents a concept of the Orion crew exploration vehicle. NASA's Constellation Program is getting to work on new spacecraft that will return humans to the moon and blaze a trail to Mars and beyond. Image courtesy:Lockheed Martin Corp.
Here are some more random questions that were submitted to our featured Scientists on the Spot that had nothing to do with their area of expertise. A few were space related, so I gathered them up to answer together.

We had two similar space travel questions. ”How many days does it take to get to the moon?” and, ”How many years does it take to get to Mars?”

First, the moon, which is closer, and rotates around the Earth. That simple fact may make you a lot of money some day.

How long it takes to get to the moon depends on how fast you are traveling and whether or not people are on the ship.

The moon is 238,855 miles from Earth. If you were to travel at a rate of 60 miles an hour from the Earth to the moon it would take165 days to get there. Luckily, spaceships can travel a lot faster.

The first man-made spacecraft to reach the moon was the Soviet Union’s unmanned Luna 2. It reached the moon in 33½ hours, meaning it traveled at an average of 7,131 miles an hour.

Manned spacecraft take longer to reach the moon as you have to take into consideration g-forces, safety and probably resting by the crew. The first manned lunar landing, Apollo 11, was launched from Earth at 1:32pm on July 16, 1969, achieved orbit around the moon some nearly 76 hours later, and made landing on the moon at 8:17pm on July 20, 1969. Apollo 12, the second moon mission, took the longest to get to the moon – over 83 hours, while Apollo 16 was the fastest at just under 72 hours. So, I would say it takes around three days to get to the moon.

Apollo 17 was the last lunar landing, back in December of 1972. NASA has plans to return to the moon in 2019.

Like going to the moon, the time it takes to get to Mars is influenced by how fast you travel, but another crucial factor is that Mars’ distance from Earth changes as the two planets rotate around the Sun, so how long it takes depends on when you leave. Recent unmanned missions to Mars included Spirit (launched June 10, 2003 – arrived January 3, 2004), Pathfinder (December 4, 1996 – arrived July 4, 1997), Mars Odyssey (launched April 7, 2001 – arrived October 24, 2001) and the Mars Reconnaissance Orbiter (launched August 12, 2005 – arrived March 10, 2006), and they average just over 6 months.

Supernova Cassiopeia A: This image from the orbiting Chandra x-ray observatory shows Cassiopeia A, the youngest supernova remnant in the Milky Way. Image courtesy: NASA/CXC/MIT/UMass Amherst/M.D.Stage et al.
Supernova Cassiopeia A: This image from the orbiting Chandra x-ray observatory shows Cassiopeia A, the youngest supernova remnant in the Milky Way. Image courtesy: NASA/CXC/MIT/UMass Amherst/M.D.Stage et al.
It would be about the same about of time for a manned spaceflight, if launched during the time when the two planets are in opposition to one another. The length of time spent on Mars will be impacted by this as well – it will either be a 30-day stay (a total 600+ day mission) or a 450+ day stay (a total 900+ day mission). Again, the difference lies in when the planets are in opposition, which only occurs every 26 months.

The final space question is “What are super novas?”

Super novas are stars blowing up. (Sweet.) Basically, the blowing up star becomes much brighter (because it is blowing up) as the material that made up the star is blown away.

More on supernovas can be found here, here or here.

Aug
08
2007

Mars.  So close, and yet not: Image courtesy NASA and ESA.
Mars. So close, and yet not: Image courtesy NASA and ESA.
So, a friend of mine wrote me the other day to tell me about upcoming spectacular Mars viewing on August 27. Here’s the email:

Two moons on 27 August

Planet Mars will be the brightest in the night sky starting August.

It will look as large as the full moon to the naked eye. This will culminate on Aug. 27 when Mars comes within 34.65M miles of earth. Be sure to watch the sky on Aug. 27 12:30 am. It will look like the earth has 2 moons. The next time Mars may come this close is in 2287.

Share this with your friends as NO ONE ALIVE TODAY will ever see it again.

My thoughts on this email...

This email is not a hoax exactly – but it is a case of once true and now outdated information mixed with bad information arising out of a bizarre “telephone game” like scenario.

Mars was this close to Earth…on August 27, 2003. And looking through a telescope at it at that time it would appear as large when viewed through the telescope as the moon does to the naked eye.

However, this close approach (called an opposition) was only slightly closer than other recent oppositions, which regularly occur every 26 months, and are closest twice every 32 years, alternately at 15 and 17-year intervals, and always between late July and late September.

Learn more about the “hoax” on Snopes.

Jul
20
2007

Mars rovers caught in severe dust storm.

"A raging dust storm on Mars has cut power to NASA's twin rovers to dangerously low levels, threatening an end to the mission. One or both rovers could be damaged permanently or even disabled, officials said." Space.com

On Tuesday, July 17, the output from Opportunity's solar Mars rover
Mars rover
panels dropped to 148 watt hours, the lowest point for either rover. On Wednesday, Opportunity's solar-panel output dropped even lower, to 128 watt hours. Mission control has ordered the Mars rover to stop communications for two days. Engineers calculate that skipping communications sessions should lower daily energy use to less than 130 watt hours.

If the sunlight is further cut back for an extended period, the rovers will not be able to generate enough power to keep themselves warm or operate at all, even in a near-dormant state. Science @NASA.

Jul
14
2007

The imaginauts take some imaginary air: Forced from the module by a bad smell, their patience is truly being tested.    (Image by frogmusuem2 on Flickr)
The imaginauts take some imaginary air: Forced from the module by a bad smell, their patience is truly being tested. (Image by frogmusuem2 on Flickr)
Russian scientists are well underway with 4th dimension mobility research, and expect to have a working time machine within the year. The time travelers, or “chrononauts,” will enter a sealed chamber, and then, supposedly, emerge 520 days in the future. Scientists do not believe, however, that the travelers will be able to return to their “home time” and so will be making a great sacrifice in the name of scientific progress.

The process for moving these people 520 days through time will take approximately 520 days. I have a bathtub that functions on very much the same principals, although it is only capable of moving me about half an hour into the future (or slightly further, if I don’t mind getting a little pruney). Like the Russian device, the bathtub does not allow for one to move backwards again through time, although that lost half hour is not always one I’d want back.

Some in the scientific community retain doubts on the validity of the time travel process. They claim that it is not so much “time travel” as it is “Big Brother, but without cameras.”

The purpose of the research, according to the Russian scientists and the European Space Agency (ESA), is not to see the future, but, oddly enough, to study the effects of a simulated journey to Mars on astronauts.

The ESA and NASA hope to send a manned spacecraft to Mars sometime in the next several decades. The thing is, a trip to Mars would be kind of like a family road trip that lasted a year and a half – 250 days to get there, 240 days to get back, and a month in between at Yellowstone (or Mars). With no stops to stretch your legs. Scientists want to know what happens once the sing-alongs stop and the chex mix runs out. I’m guessing something like “Lord of the Flies,” or “Leprechaun 4: Leprechaun in Space.” But I’m no scientist.

Volunteers from all over Russia and Europe have been fighting for the chance to be placed in a 550 cubic meter pod with five strangers for 520 days straight. With the exceptions of weightlessness and exposure to radiation, all aspects of the interplanetary trip will be simulated. The module will not be opened for anything outside of a major emergency, and there will be a twenty-minute communication delay between Earth and the “space ship.” Also, the three volunteers who will be landing on Mars (as it were) will have to spend a month in a separate chamber, “lying on their backs with their heads lower than their feet,” to simulate the effects of zero gravity. Prospective volunteers expect this portion of the experiment to be “super crappy.”

Applicants should be “Healthy and professional… and intellectually tough.” So I’m out, but anyone else who’s interested in a trip to Mars, with no Mars, should get a hold of the ESA.

The Guardian’s article on the project.

Jul
11
2007

Venus and Mars are alright tonight: They may not teach us much about conditions on Earth, but they provide hours of entertaining temperature conversion!  Photo of Venus (left) from NASA; photo of Mars (other guy) from the Library of Congress.
Venus and Mars are alright tonight: They may not teach us much about conditions on Earth, but they provide hours of entertaining temperature conversion! Photo of Venus (left) from NASA; photo of Mars (other guy) from the Library of Congress.

As Science Buzz's resident global warming skeptic, I've taken a lot of shots at Al Gore over the years. Today, however, I find myself in the unusual position of having to defend him against unfair attacks. Somewhat.

In an editorial last Sunday, Gore stated:

“Consider this tale of two planets. Earth and Venus are almost exactly the same size, and have almost exactly the same amount of carbon. The difference is that most of the carbon on Earth is in the ground - having been deposited there by various forms of life over the last 600 million years - and most of the carbon on Venus is in the atmosphere.

As a result, while the average temperature on Earth is a pleasant 59 degrees, the average temperature on Venus is 867 degrees. True, Venus is closer to the Sun than we are, but the fault is not in our star; Venus is three times hotter on average than Mercury, which is right next to the Sun. It's the carbon dioxide.”

This got a bunch of bloggers to thinking. George Reisman went to a NASA website and found an interesting comparison:

PLANET Venus Earth Mars
CO2 IN ATMOSPHERE 96% 0%* 95%
AVERAGE TEMPERATURE 867˚F 59˚F -81˚F

*Not quite true: Earth’s atmosphere is 0.035% CO2.

So, planets with lots of carbon in their atmosphere can be either broiling hot or icy cold.

(Another writer, Evan Kayne, complained (seventh item) the comparison isn't fair; Reisman didn’t take into account the fact that the atmosphere on Mars is only 1.3% as thick as Earth’s. James Taranto of the Wall Street Journal re-did the calculations, and concluded that frigid Mars still has 34x as much CO2 per cubic foot of atmosphere as the Earth does.)

So far, Al isn't looking too good. But then, blogger David Downing thought he'd discovered another problem. According to the NASA site, Mercury has an average temperature of 452˚ Kelvin, while Venus has an average temp of 726˚ Kelvin. That’s only 1.6 times hotter, a far cry from what Gore had claimed!

Wait a minute. What’s this “Kelvin” scale and why is Downing using it? Well, all temperature scales measure energy. And on the Kelvin scale, 0 degrees means “no energy AT ALL.”

This makes it very easy to compare the energy in different systems. In Celsius, 0 degrees doesn’t mean “zero energy;” it means “the amount of energy in frozen water” -- which may seem chilly to you and me, but at a molecular scale, it’s got plenty of heat. (0 degrees Fahrenheit is apparently the amount of energy in a mix of ice, water, and ammonium chloride.) Comparing 25˚F to 50˚F is tricky, because the scale doesn't stop at 0. As any Minnesotan knows, it goes wayyyyy lower than that!

(It’s kind of like saying “Mike is five years older than me; Vic is 10 years older than me; therefore, Vic is twice as old as Mike.” That would only be true if I were 0 years old. If I were, say, 47, then Mike would be 52 and Vic would be 57, and the differences would be much less impressive.)

So, Downing assumed Gore must have been working in Fahrenheit, and believed that if Venus is 867˚F and Mercury is 289˚F, then Venus is three times hotter. Ha ha, what a silly mistake! I was all prepared to poke fun at Al for this glaring error, until I realized – Mercury isn’t 289˚F. According to NASA, it’s a toasty 354˚F.

So, where did Al get 289˚F? I looked in a bunch of sources -- no one was even close. Wikipedia listed Mercury at a mere 26˚F. (The side facing the Sun broils; the side turned away freezes; this is an average.)

But then I noticed -- 26˚F is 270˚K. And Wikipedia lists Venus at 735˚K . Using the proper Kelvin scale, that works out to 2.7 times hotter than Mercury. Not quite 3 times, but in the ballpark. And, to be fair, Wikipedia gives Mercury a range of temperatures, and “3x hotter” fits comfortably within that range.

So, it turns out Gore was closer to being right than he’s given credit for. He WAS working in the proper Kelvin scale. He was just relying on figures from Wikipedia rather than from NASA.

I don’t know if all this has taught us anything about global warming. But man, have I learned a lot about planetary atmospheres, temperature scales, and math! Thanks, Al!

UPDATE: Evan Kaye had claimed that the atmosphere on Mars is only 2% as thick as Earth's. James Taranto, using figures from the NASA site linked to above, calculated that it is actually 1.3% as thick as Earth's. We have corrected the figure.

From the comfort of your PC. Visit Google Moon or Google Mars.

If you have a high speed internet connection I recommend viewing this video. I wonder if it will ever get back out?
NASA video explaining Opportunity's plunge into Victoria Crater.

The Mars rover, Spirit's, solar arrays increased their output by 120 watt-hours yesterday. The 20% increase is probably due to gusts of wind cleaning some dust off the solar panels.

Photos from the Mars rover Opportunity appear to show small puddles of liquid water. Since water is necessary for life as we know it, this raises the possibility that life may exist on Mars. Some scientists, however, believe that liquid water could not last on the Martian surface, and that this is actually ice.