Quickie Questions - Solar System - Mars and Its Moons

Date Answered Questioner (age, location) Question Answer
May 11, 2010Marra (Idaho)How far away is mars from the sunThe orbits of the planets are not perfectly circular, they have an ellipsoidal shape. Mars inimum distance from Sun is 205 million km (128 million miles) and its maximum distance from Sun is 249 million km (155 million miles).
May 4, 2010stephanie (united states of america)is there water on mars?Laboratory tests aboard NASA's Phoenix Mars Lander have identified water in a soil sample. See full NASA article here.
March 9, 2010daisy (america)has there ever been water on marsA very recent discovery confirm the long held idea of water on Mars. The NASA'a article NASA Spacecraft Confirms Martian Water, Mission Extended describe in some details this important confirmation.
March 5, 2010Diego (USA,TX)Mars is located where in our solar system(how far from the sun).Mars is the fourth planet from the Sun. It follows an orbit between Earth's orbit and the asteroids belt. Mars minimum distance from Sun is 205 million km (128 million miles) and its maximum distance from Sun is 249 million km (155 million miles).
February 17, 2010alyson (canada)What is the distance from the Sun to Mars in astronomical units ?It is about 1.52 AU.
February 17, 2010alyson (canda)What is the maximum temperature on Mars ?The temperature on Mars varies from -129 oC to 0oC ( -200oF to 32oF).
January 14, 2010isabel (newyork/usa)was there ever life on Mars?Scientists have not found any trace of life outside Earth, but the search continues.
December 21, 2009Jennifer (CA)My question is is there life on Mars?Although this has been for a long time focus of scientific study, there is so far no proof of any life form in Mars.
December 17, 2009Susan (Australia/NSW)How was South Candor formed?A good explanation of the propossed processes that created South Candor and other interesting topografic elements can be found in the article Melas, Candor and Ophir Chasmas: centre of Valles Marineris.
August 21, 2009ontiveros (Mexico)why mars is called like that?Mars is much like Venus-- it's very bright and therefore easily spotted in the night sky. Because of this, we don't know who exactly discovered Mars. We do know it was named after the Roman god of war, because its reddish color reminded people of blood.
August 11, 2009Jasten (Wisconsin)Is Mars Rocky?Yes, Mars is one of the Rocky planets. Mars composition seems to be the of the same kinds of minerals as the Earth has, with lots of silicates and some iron oxides that gives it its reddish color.
June 2, 2009Ahsan (U.S.A)what is direction of spin of marsMars, as seen from his north pole, spins counterclockwise.
May 7, 2009noor (karnataka/India)has water been find in mars?Laboratory tests aboard NASA's Phoenix Mars Lander have identified water in a soil sample. See full NASA article here.
May 7, 2009Hannah (USA Wisconsin)How do you grow plants on Mars so you could live there some day.Terraforming another planet means to change the planet to make it more like the planet Earth. This would involve making changes to a planet's atmosphere, soil, and temperature. And these are the basics! These changes are easier said than done, but not entirely impossible. Since we have never terraformed a planet, it's hard to say how long it would take, but surely it would take hundreds of years to make a good start!
April 17, 2009brittany (nc/usa)if an object weighed 100 pounds on th earth, what would it weigh on Mars?????

THNX,
Brittany
The weight of a body depends on the mass and the gravitational force that acts over this mass. Mass is a permanent magnitud (it stays the same from planet to planet), but weight will change. Mars gravity is 37 m/s2, 0.37 of Earth's gravity. The body in your example would weight 37 pounds in Mars.
April 14, 2009Matthew (United States/Texas)What will happen to mars in the future?The Sun is a medium size star. It will become a red giant. At this point, the Sun will have expanded to cover all the interior planets, including Mars and Earth. The outer layers then cool to about 3000 K and becomes a red star of a huge size. After a few more millions of years, the star evolves into a white dwarf-planetary nebula system.
February 26, 2009sana (UAE)who discovered mars?Mars is much like Venus-- it's very bright and therefore easily spotted in the night sky. Because of this, we don't know who exactly discovered Mars. We do know it was named after the Roman god of war, because its reddish color reminded people of blood. More information on our web page Discovery of Mars.
February 3, 2009alvarez (h-town)how many seasons are there in marsPlease, visit this web page for a detailed explanation of the seasons in Mars.
January 13, 2009Noy (Canada)what year was Mars discovered?Mars is much like Venus-- it's very bright and therefore easily spotted in the night sky. Because of this, we don't know who exactly discovered Mars. We do know it was named after the Roman god of war, because its reddish color reminded people of blood. In 1659, Christian Huygens discovered a strange feature on the surface of the Red Planet. It was later called the Syrtis Major. We have been scared of Martians ever since. In 1802, one scientist was so convinced there was life on Mars that he wanted to draw huge figures in the snow to signal the Martians!
November 3, 2008Michael (Ontario/Canada)what is in the valcanos on marsThe large shield volcanoes on Mars have effusive eruptions which are relatively quiet and basaltic in nature. They were built from large magma chambers deep within the Martian crust. More information here.
September 26, 2008Jenny (Iowa)is mars gravitational pull the same in its whole surface?No, gravity is inversely proportional to the distance to the center of Mars (or any other object). A point a the top oh a higher elevations will hve a lower gravitational pull. This is valid everywhere!
September 16, 2008Kelly (Malaysia)Did Mars have water?It al lindicate that there was and still is water in Mars. The Mars mission Phoenix recently found ice under a fine layer of dirt. This is a direct confirmation of the existence of the precious liquid on our neighbor planet.
September 15, 2008Wayne (colo)What are the new possibilities of the discovery of ICE on mars? Life? God?The finding of proof of water on Mars is a first step toward learning whether Mars is hospitable or if there was life before on this planet, because all life (as we know it) requires water.
September 12, 2008zachariah (usa colorado)how meny volcanoes does mars haveThere are less than 20 named volcanoes on Mars. Visite our web page Martian Volcanoes for more information.
August 21, 2008bergmann (nsw)how far from the sun doesmars orbit?For Mars: Minimum Distance from Sun: 205 million km (128 million miles) Maximum Distance from Sun: 249 million km (155 million miles)
August 19, 2008dulce (colorado)is it true that you send two robots to mars and that one of them dissapeared?Actually no, the twin rovers landed on Mars in January 2004, on missions originally planned to last 90 days. However, NASA is extending, for a fifth time, the activities of the Mars Exploration Rovers, Spirit and Opportunity, possibly through 2009. More information at NASA.
August 15, 2008dave (sri lanka)how big is mars in milesMars diameter is 6,785 km (4,217 miles).
August 14, 2008Nicholaus (VA/United States of America)Does Mars have frozen water on its surface?By melting icy soil in one of its lab instruments, the Phoenix spacecraft confirmed the presence of frozen water lurking below the Martian permafrost. Until now, evidence of ice in Mars' north pole region has been largely circumstantial. See full article here.
July 2, 2008cheryl (Missouri)How many orbits has Mars made since Dec. 1993?A year in Mars (a full revolution about the Sun) takes 1.88 Earth years. From December 1993 to December 2007 Earth has completed 15 revolutions around the Sun (15 Earth years) but Mars only 7.97 revolutions.
June 30, 2008whitney (fl)what would happen if some one went to mars with out a space suit and other stuff you need?There won't the oxygen necessary to live, the traveler would be expossed to dangerous radiations, and many biological processes would be affected by the lack of atmospheric pressure (Mars atmosphere is much thinner than that of Earth, with a surface pressure averaging 1/100th that at the surface of the Earth) and the much lower gravity (0.37% of Earth's).
May 28, 2008Ryan (Delaware)How long would it take to reach Mars from Earth traveling at 600,000 mph?The average smallest distance between Mars and the Earth is 48 million miles (78 million kilometers). If we can keep a constant speed of 600 000 mph, we will reach Mars in about 80 hours.
May 16, 2008Jemimah (Philippines)How hot is Mars?Mars temperature varies from : -129oC to 0oC ( -200oF to 32oF).
May 7, 2008ryley (canada)How thick is the mantle of Mars?It is generally accepted that the mantle of Mars 800 to 1,100 miles (1 300 - 1 800 km) thick.
April 1, 2008mackenzie (kentucky)what is 1 fact about mars?Few facts about Mars: Diameter: 6,785 km (4,217 miles) Mass: 0.64x1024 kilograms (0.11 x Earth's) Density: 3,933 kg/m3
March 17, 2008melissa (Georgia)What is the temp on Mars?Mars' temperature varies from -129oC to 0oC ( -200oF to 32oF).
March 17, 2008melissa (Georgia,Lawrensville)What is the temp on Mars?Mars' temperature varies from -129oC to 0oC ( -200oF to 32oF).
March 4, 2008kathy (CA , USA)how did mars get its name?Ares was the Greek god of war, was identified with the Roman god, Mars. He always acted like a strong warrior and a strong desire for violence. He enjoyed the great noise of battle, and he loved bloody warfare. Conflict and mindless killing was how he liked to spend the day. Mars was the father of the famous Roman heroes Romulus and Remus who founded the city of Rome. For that reason, he was believed to come to the aid of Romans in times of crisis. For other related myths, please visit our web page Myths About Mars.
January 24, 2008isabel (United States/Suprise)who discovered Olympus Mons?The martian volcano Olympus Mons, the largest volcano known on the Solar System, was discovered by Giovanni Virginio Schiaparelli on November 10, 1879.
January 12, 2008Sarah (Virginia)What is the interior composition of Mars?Scientists believe that Mars's interior consists of a crust, mantle, and core as if Earth's interior. Because no spacecraft has ever brought instruments that can study Mars's interior we don't know much about the exact composition of Mars interior.
January 3, 2008Marzipan What is Mars' air resistance like compared to Earth's?The atmosphere of Mars is much thinner than that of Earth, with a surface pressure averaging 1/100th that at the surface of the Earth. The air resistance should be much lower that in our planet.
December 18, 2007Bella (California)What is Mars nicknameOur page Myths about Mars offers a good review of the names and myths associated with this planet.
September 25, 2007Jeff Will Mars be more visible from the earth later this month?If you are refering to Mars being "as big as the Moon", no. This story is not true. It is a myth that has been floating around the Internet for a few years. Mars will never look any larger than a bright star to the naked eye. The next close approach between Earth and Mars will be in mid-December of 2007; the planets will pass within about 88 million km (55 million miles) of each other. In August 2003 the two planets were closer together than they had been for a very long time. See the following pages for more: Headline Universe, Mars Orbit.
We try to highlight at least some of the major ongoing astronomical events; but unfortunately do not have enough staff to cover all of them. (Thanks to Randy).
September 12, 2007Ellee (brisbane)1. How much Gravity does Mars and all the other planets have?Mars' surface gravity is 3.7 m/s^2 (0.37 x Earth's). For the gravity values for the rest of the planets, vist our web page Our Solar System and select "Planetary Facts" for each planet.
August 21, 2007Jake (New Zealand)Why are mars clouds made out of crystals?The atmosphere of Mars is composed mainly of carbon dioxide (95.3%), nitrogen (2.7%), and argon (1.6%), with small amounts of other gases. Oxygen, which is so important to us on earth, makes up only 0.13% of the atmosphere at Mars. There is only one-fourth as much water vapor in the atmosphere.
August 17, 2007Fiz (New Zealand)When do the least favorable opposition between Mars and Earth occur?If Mars is at opposition and also near its farthest point from the Sun (aphelion), we have an "unfavorable opposition". Under this condition the disk of Mars appears smaller than at an "average opposition". There will be such a condition in 2010.
July 26, 2007brad (michigan, america)if mars has so much carbon dioxide in its atmosphere, how come it is not hot like venus?Just because it is much farther from the Sun.
July 19, 2007Milly (nz)On mars how heavy would a 10kg kid weigh???Our planet gravity is 9.8 m/s2. Mars' is 3.7 m/s2 (0.37 x Earth's). The same proportion will apply to weight: 10 kg x 0.37 = 3.7 kg.
July 19, 2007Milly (nz)What is so special about marsNot sure why Mars is special, but you can get your own opinion from the following information. Some facts about Mars: Diameter: 6,785 km (4,217 miles) Rotation Period about Axis: 24.6 hrs Mass: 0.64x10^24 kilograms (0.11 x Earth's) Revolution Period about the Sun: 1.88 years Mars is very bright and therefore easily spotted in the night sky. Because of this, we don't know who exactly discovered Mars. We do know it was named after the Roman god of war, because its reddish color reminded people of blood.
July 18, 2007Steven (FL)WAs THere Ever Water On Mars ?Plenty of clues suggest that liquid water once flowed on Mars --raising hopes that life could have arisen there-- but the evidence remains inconclusive and sometimes contradictory. The NASA article The case of the Missing Mars Water dicusses in detail this topic.
July 13, 2007jinnie (Mars)What are marses moons made out of????Phobos and Deimos are examples of what are called minor satellites: small chunks of rock in orbit around planets (very differet from large satellites like the Earth's Moon). These moons are very irregular in shape.
July 13, 2007Arial (MA)How do you know there was a sea on Mars?The answer to your question escapes this section, but this NASA webpage covers the topic in detail.
July 11, 2007Charlie(australis)what is the gravity on mars ????????The value of gravity on the surface of Mars is 3.7 m/s2 (0.37 x Earth's).
July 9, 2007jimmy (texas)Volcanoes have been discovered on the moon and planets. What would the volcano cone Olympus Mons on the planet Mars be considered?Olympus Mons is a shield volcano 624 km in diameter, 25 km high, and is surrounded by a 6 km high scarp.
May 30, 2007eddy (A.L/U.S.A.)what degree does mars tiltThe tilt of Mars' axis is 25o 12".
May 21, 2007kelly (nz)i need to know about the surface of mars. What is it made from? how would you walk on it? what are the problems/challenges in the way of walking on mars?The uniquely red global surface of Mars is marked by many interesting features - some like those on the Earth and others strangely different. The reddish color is caused by rust (iron oxide) in the soil. Some of these features are; volcanoes, canyon systems, river beds, cratered terrain, and dune fields. Of these features, the most interesting includes the apparently dead volcano Olympus Mons, which rises 23 km (~75,000 ft) above the surrounding plains and is the highest known peak in the Solar System. Valles Marineris is a giant canyon system that runs about 2,500 miles across the surface of the planet and reaches depths of 6 km or 4 miles (for comparison, the Grand Canyon is not more than 1 mile deep). Visit our web page Our Solar System and select Mars for a wealth of information about the Red Planet.
April 4, 2007Kasie (Utah)How big is Mars?Mars' diameter is 6 785 km (4,217 miles), and has a mass of 0.64x1024 kilograms (0.11 x Earth's). For more interesting facts about this planet, visit our web page Mars Statistics.
March 27, 2007Anastasia (connecticut, u.s.a)How many craters are on the planet Mars?There are hundreds of thousands of craters in mars surface, and only some with names. Visit Wiki-List of Craters on Mars for a list of named craters.
March 27, 2007emily (ohio)why is mars hot?Mars is too far from the Sun (about 220 million km) to be really "hot". During winter, Mars can get as cold as -124 oC (-191 oF), and during summer Mars can reach up to -30 oC (-24 oF).
March 23, 2007alex (Il,America)how big is Mars in kilometersMars has a diameter of 6 785 km (4,217 miles), and a mass = 0.64x1024 kilograms (0.11 x Earth's).
March 5, 2007Antonio is it true that deimos which is the satellite of mars contains gas which is oxygen?Deimos is composed of rock rich in carbonaceous material, much like C-type asteroids and carbonaceous chondrite meteorites. There is no oxygen in Deimos.
March 1, 2007 Does it snow on mars?Mars poles are covered by ice. Visit our web exploratour Comparing the Surfaces of Earth and Mars for many views of Mars surface.
February 12, 2007DAN (USA)whats the tempurature on mars? whats the size of mars? whats it made of? iam doing a project and need this infoThe temperature on Mars varies from -129 degree C to 0 degree C (-200 degree F to 32 degree F). Mars' diameter is 6,785 km (4,217 miles), its mass is 0.64x10^24 kilograms (0.11 x Earth's), and its density is 3,933 kg/m^3.
February 5, 2007carla (usa)how many rings does pulto and mars have?Mars and Pluto do not have rings, but they have moons: Mars has two moons: Phobos and deimos. Pluto has 3 moons, Charon (very large) and other two fairly small moons: S/2005 P1 and S/2005 P2.
January 25, 2007Anna (Florida)Can you tell me you're top ten facts about Mars?The uniquely red global surface of Mars is marked by many interesting features.The reddish color is caused by rust (iron oxide) in the soil. Some of these features are; volcanoes, canyon systems, river beds, cratered terrain, and dune fields. For more information on this planet, visit our web page Mars.
January 23, 2007Jessica (CA)How many rings does Mars have?Mars doesn't have rings, but it does have two moons: Phobos and Deimos.
January 22, 2007savannah (ma)how many moons does mars have?Mars has two moons: Phobos and Deimos. For a current list of all the moons visit Moons in our Solar System.
January 21, 2007 how many moons does mars haveThe moons of Mars are: Phobos and Deimos.
January 19, 2007samantha (usa)does mars have rings?NO, Mars does not have rings, but it does have moons: Deimos and Phobos, discovered in 1877 by A. Hall.
January 16, 2007stacy (wa)what is the distance to the sun from mars.Mars' minimum distance from the Sun is 205 million km (128 million miles), and its maximum distance from the Sun: 249 million km (155 million miles). For more interesting facts about this planet, visit our web page Myths About Mars.
December 20, 2006-- I have been looking all over for this answer to this question but havent been able to find it: What is the gravity like on mars?The surface gravity on Mars is 3.7 m/s^2 (0.37 x Earth's)
December 20, 2006Tamra (vic)when and where was mars discovered?
is mars 230000km from the sun?
how long is a day and a year on mars?
Mars is much like Venus-- it's very bright and therefore easily spotted in the night sky. Because of this, we don't know who exactly discovered Mars. We do know it was named after the Roman god of war, because its reddish color reminded people of blood. Mars’ minimum distance from the Sun is 205 million km (128 million miles), and its maximum distance is 249 million km (155 million miles). A Martian year (revolution period around the Sun) is 1.88 earth years. A Martian day (rotation period about Axis) is 24.6 hours. For more information about Mars, please visite our web page Mars
December 13, 2006Jasmin (California)Who discoverd Mars?Mars is much like Venus-- it's very bright and therefore easily spotted in the night sky. Because of this, we don't know who exactly discovered Mars. We do know it was named after the Roman god of war, because its reddish color reminded people of blood. More information can be found in our page Discovery of Mars.
December 13, 2006Alyssa (California)HELP!!!!! I'm doing a report on Mars and need to know what it is made of! Please do tell.Composition of Mars: The atmosphere is composed mainly of carbon dioxide (95.3%), nitrogen (2.7%), and argon (1.6%), with small amounts of other gases. The surface seems to have abundant silicates and traces of iron oxides, which is responsible for the reddish color.
December 13, 2006Hannah (Australia)What are the common elements present and their state of matter (Solid, liquid or gas) on Mars?Composition of Mars: The atmosphere is composed mainly of carbon dioxide (95.3%), nitrogen (2.7%), and argon (1.6%), with small amounts of other gases. The surface seems to have abundant silicates and traces of iron oxides, which is responsible for the reddish color (solid).
December 13, 2006Bonnie (Georgia)what formed the terrain on mars?Martian Cratered Terrain: Craters can be wiped out over time, so a surface which has many craters is very old. The lowlands of Mars have fewer craters, and seem to be younger than the highlands of Mars, which have many craters and is a very old portion of Mars. The highlands of Mars are in the southern hemisphere, which means that the southern hemisphere is the oldest portion of Mars. The Tharsis Ridge, where the volcanoes of Mars are found, is lightly cratered, which means that it is also a younger portion of Mars. For more information, please visit this page.
December 13, 2006sally (united states ,kansas)what is mars'basic composition?The atmosphere is composed mainly of carbon dioxide (95.3%), nitrogen (2.7%), and argon (1.6%), with small amounts of other gases. The surface seems to have abundant silicates and traces of iron oxides, which is responsible for the reddish color.
December 11, 2006Rumesha (Georgia)How far is Mars from Earth?Because all the planets are constantly rotating around the Sun, it is useful to establish a frame to determine the average distance between two of them. Let’s assume for this calculation that Mars and Earth are aligned with the Sun, and use their average distance to the Sun to determine the average distance between them: Mars average distance to the Sun: 227 million km (141.5 million miles) Earth average distance to the Sun: 149.0 million km (92.8 million miles) Difference (average distance between the two planets): 78 million km (48.7 million miles)
December 11, 2006Janaisha (nj)Who discovered Mars-the planet?Mars is much like Venus-- it's very bright and therefore easily spotted in the night sky. Because of this, we don't know who exactly discovered Mars. We do know it was named after the Roman god of war, because its reddish color reminded people of blood. More information can be found in our page Discovery of Mars.
December 9, 2006-- what is the roation period of marsMars Revolution Period about the Sun is 1.88 Earth years. Mars Rotation Period about its Axis is 24.6 hrs.
December 9, 2006megan (Pennsylvania U.S.A.)What are the orbits like on Mars?The eccentricity of Mars' orbit is 0.093, which make it very close to a circular shape. Mars moves at 24.1 km/s, and completes a full orbit around the Sun in 1.8809 Earth years.
December 9, 2006Jasmin (California)Why is Mars red?The reddish color of Mars is caused by rust (iron oxide) in the soil.
December 1, 2006Eric (Indiana/ United States of America)Who Named Mars?Mars was named after the Roman god of war, because its reddish color reminded people of blood.
December 1, 2006Cat (USA)Who dicovered mars?Mars is much like Venus-- it's very bright and therefore easily spotted in the night sky. Because of this, we don't know who exactly discovered Mars. We do know it was named after the Roman god of war, because its reddish color reminded people of blood. More information can be found in our page Discovery of Mars.
November 30, 2006paris (Virginia,Unitedstates)How long is a day and year on MarsMars takes 1.88 Earth years to complete one full revolution around the Sun (Mars year) and 24.6 hours to complete a rotation about its axis (Mars day). For more interesting facts about Mars visit this page.
November 12, 2006liz (australia)does mars take twice as long as earth does when orbitting the sun?Actually Mars takes 1.88 Earth years to complete one full revolution around the Sun. For more interesting facts about Mars visit this page.
October 23, 2006jannet (Newzealand)how long does it take for mars mars toorbit the sunThe period in which Mars completes a revolution around the Sun is 1.88 "Earth year". For more interesting information and statistics about Mars visit this page.
August 8, 2003Carol(North Carolina)I have received an e-mail message regarding Mars and the earth. Before I forward the information to our science teachers in the county, I wanted to verify the info. The e-mail that I received indicates that during August Earth will "catch up with Mars, culminating in the closest approach between the two planets in recorded history. The next time Mars may come this close is in 2287. The encounter will culminate on Aug 27 when Mars comes to within 34,649,589 miles of Earth and will be the brightest except for the moon in the night sky. It will attain a magnitude of -2.9 and will appear 25.11 arc seconds wide. At a modest 75-power magnification, Mars will look as large as the full moon to the naked eye. Mars will be easy to spot. At the beginning of August it will rise in the east at 10 P.M. and reach its azimuth at about 3 A.M. By the end of August when the two planets are closest, Mars will rise at nightfall and reach its highest point in the sky at 12:30 A.M.... No one alive today will ever see this again...."The email you received is mostly correct. The figure we've seen that seems most reliable for the separation distance is 34,646,418 miles. Also, there is some debate concerning exactly how long ago Mars and Earth were closer together. Sources agree that it has been thousands of years. The likely figure is 59,619 years, but there is some uncertainty in this number because of the difficulty in determining the influence of the gravity of some large asteroids on the orbit of Mars. There will be a closer approach on August 28, 2287. For more details, view our Headline Universe news article about the event and an interactive animation illustrating the orbital motions of Earth and Mars.
August 3, 2001Alyssa (Middle School, USA)When was Mars discovered?No one really knows. Mars is often quite bright, so it was likely seen in the night sky by the earliest people. For more information, see our page on the Discovery of Mars.
July 16, 2001Paul (12, Florida, USA)Where is Mars located in the sky? I understand that it is continually moving. I just want to know what coordinates I need to put in my telescope so I can see it at night. Is there some web site I can go to in order to keep track of its location?Right now (July 2001), Mars can be seen in the constellation of Scorpio. You might try the web site for the maker of your telescope for coordinates, or look at the web site for Sky and Telescope magazine for more information on where to find specific objects in the night sky.
May 14, 2001Nikki (10, Georgia, USA)Has a spacecraft ever been to Mars?Sure! Here's a list of unmanned missions to Mars. There haven't been any manned missions to Mars - yet!
May 14, 2001Taylor (12, Ohio, USA)Why do Mars microprobes have to be slammed into the planet's surface at such a high speed?The Mars microprobes were attached to the Mars Polar Lander. The probes were released and were suppose to penetrate the Martian atmosphere and the Martian surface in the south polar region. They were suppose to slam into the surface at such a high speed because scientists actually wanted the probes to penetrate the surface as deeply as possible.

One of the most important pieces of data these 2 probes were to return was whether there is water ice below the surface of Mars. Unfortunately, on December 3, 1999, contact with the probes was lost.

April 24, 2001SamHow long does it take to get to Mars with our current technology?The 2001 Mars Odyssey just launched on April 7, 2001. It is expected to get to Mars on October 24, 2001...so, about 6 and a half months.
March 7, 2001Ryan (Minnesota, USA)What planet did the space probe Pathfinder land on?Mars!
January 29, 2001Michelle (Pennsylvania, USA)Olypmus Mons is the highest mountain on Mars. About how many times higher is it than Mt. Everest, Earth's tallest mountain?Olympus Mons is the highest volcano in the solar system! It is about three times as tall as Mt. Everest!
December 22, 2000Joline (Ontario, Canada)MARS! I'm doing a project on Mars and I was just wondering what the color of this planet is!Mars is known as the Red Planet.
December 14, 2000Katie I have a report to do on the volcano Olypus Mons and I was wondering if you could send me some information on it.Olympus Mons is the largest volcano in our solar system. Besides this link, try searching on our site for "Olympus Mons" - lots of other pages show up!
September 6, 2000Patience (Indiana, USA)What are two unique physical characteristics of Mars separates it from the other eight planets?There are lots of unique things about Mars. One unique characteristic is that Mars has the largest volcano in the solar system, Olympus Mons. (It also has deep valleys!) Mars is also the only planet with two moons, Phobos and Deimos.
August 16, 2000Jacqualine (Singapore)What can we see from the sky if we are on Mars?If you were on the Red Planet, you would see pretty much the same thing we see from Earth. The only difference is, you would see the Earth instead of Mars!
June 23, 2000Rebekah (Illinois, USA )Is there chemical or mechanical weathering on Mars, and what kind of erosion is there?This page should give you a good idea of the weathering on Mars.
June 16, 2000Ally (Ohio, USA )What are the seasons on Mars?Seasons occur because of the tilt of a planet while it revolves around the Sun. The length of the Martian day (24 hours and 37 minutes) and the tilt of its axis (25 degrees) are similar to those on Earth (24 hours and 23.5 degrees), so its seasons should be similar to those of the Earth.
May 17, 2000Sally (Canada)Will a compass work on Mars?A compass will work on any planet that has a magnetic field. Since Mars has a magnetic field, you could use a compass on your next visit.

But if you plan to take a vacation to Venus any time soon, you better have a really good map. Venus doesn't have a magnetic field, so your compass will be useless there!

May 12, 2000Erin (South Caroline, USA)Why is Mars red?The soil of Mars has a lot of rust, or iron oxide, in it. If you don't know what rust looks like, look at the metal around your house. You will probably find some!
March 3, 2000-- (Illinois, USA)What is the biggest canyon on mars?Valles Marineris is a large system of canyons that stretches 4000 km (2500 mi) along the equator of Mars.
March 2, 2000Stephen (England)The Moon is moving 1 centimeter each year away from Earth, but Mars's moon Phobos is getting closer. Why is Phobos getting closer to Mars's surface and will it crash into its surface?There is a certain distance from the planet where an object's velocity balances the gravitational force from the planet. This is the "synchronous orbit radius" for that object. In the case of the Moon, it is orbiting the Earth at the Moon's synchronous orbit radius. So the force of gravity from the Earth is balanced by how fast the Moon is moving.

However, in the case of Phobos, it is orbiting Mars at a height lower than Phobos' synchronous orbit radius. That means that the speed of Phobos isn't enough to counteract the force of gravity from Mars, and eventually (100 million years or so) Phobos will crash into Mars.

January 25, 2000Angie (Florida, USA)What is the atmospheric pressure on Mars compared to Earth?The average pressure on the surface of Mars is only 7 millibars which is less than 1% of Earth's.
August 12, 1999Brenda I heard that you can buy property on Mars. Is this a proven fact or is this another rumor going around?If anyone offers to sell you land on Mars, they are breaking the law! In 1967, the United Nations adopted an international law, which clearly states it is a violation to sell any celestial object or its land. So, keep you wallet in your pocket the next time someone says they have dirt cheap Martian land!
March 13, 1999Matthew (Alberta, Canada) With the fact that little is known about Mars in mind, where can I find a cross-section of the interior of Mars?The Mars Pathfinder has brought back this information about the interior of Mars.
February 5, 1999Andrew (England)Is there an on-line map showing the location of the Lacus Solis on Mars ? Here is one, courtesy of Dan Troiani and Carlos Hernandez. Solis Lacus is in the left third.
January 13, 1999Travis Is there a way that I could find out the date and time on Mars? I want to put its time and date on my watch. If you know some simple math or more advanced on how I can figure out the time and date please let me know. The length of a day on Mars consists of 24 hrs, 37 min. There are 687 Earth days in a Mars year. There is really no set date and time on Mars, since these are always arbitrarily set by humans. For example, different civilizations have used many different calendars throughout history.
January 6, 1999William Can auroras happen on Mars?No. The aurora is an atmospheric occurance, and since Mars has very little atmosphere, there can be no aurora on Mars.
September 21, 1998Allison (Oregon, USA)Why is Olympus mons so large?The reason Olympus Mons is so large is because of the way Mars cooled. It cooled very quickly, to form a solid crust. Then, some of the still-hot material inside Mars pushed up from the core to form a large bulge, which is Olympus Mons.
May 16, 1998Simon (Pennsylvania, USA) What is the average surface temperature of Io, Ganymede, Callisto, Phobos and Triton?The average temperature of Io is 130K. The average temperatures for Ganymede, Callisto, Triton are 117K, 126K and 34.5K respectively. As far as I know, the average temperature of Phobos is not yet known.
May 12, 1998No info given... How old is Mars?About 4 billion years old.
March 24, 1998Jacqueline (Michigan, USA) What is the latest information regarding plate teconics and Mars? How about our moon?Since Mars is much smaller than Earth, the amount of heat inside is less. This limits tectonism. As a result, we do not see the plate tectonics that Earth has. The surface of Mars is just one large plate. Instead of plates, we see canyons and crate rs formed by rifting, erosion, and landslides.
The moon also is a single plate, deeply pitted and cratered.
March 17, 1998Laura (New York, USA) What is Olympus Mons?Olympus Mons is a volcano on Mars. It is HUGE -- the highest know peak in the solar system. It rises 23 kilometers (about 75,000 feet) above the surrounding Martian plains!
February 18, 1998Alexandra and Lisa(Maryland, USA)We read that Mars is the most similar planet to Earth. In what ways are these two planets alike?Like Earth, Mars is a rocky planet, meaning it has a solid surface. Mars has an atmosphere composed mainly of carbon dioxide. Its day length is also close to that of Earth, 24 hours and 37 minutes. Mars has frozen water on its surface, at the polar ice cap. Its temperature range is fairly moderate, going from -116 to 32 degrees F. No other planet even comes close to having conditions suitable for humans. For this reason, Mars is the only planet chosen for possible human exploration.
January 8, 1998Jimmy (Florida, USA)Since there is so much wind on Mars, why doesn't the wind erode the creaters on the planet?The wind on Mars moves very quickly so the craters are continually eroded. Since the Martian atmosphere is thinner than the Earth's, the wind's force isn't as strong. Because of this, craters don't erode as fast as they would on Earth.
December 31, 1997Alison (Georgia, USA)How long would it take to terraform Mars?Terraforming another planet means to change the planet to make it more like the planet Earth. This would involve making changes to a planet's atmosphere, soil, and temperature. And these are the basics! These changes are easier said than done, but not entirely impossible. Since we have never terraformed a planet, it's hard to say how long it would take. In my opinion, it would take hundreds of years to make a good start!
December 30, 1997Christie (USA)How hot is Pluto? Mars? Mercury?Pluto:-229o C
Mars:-82o C to 0o C
Mercury:-184o C to 427o C
This information is available for every planet on each planet's Planetary Facts page.
December 30, 1997Bri (Colorado, USA)Is it possible to send a probe to Mars, gather information on Mars and its atmosphere? Then we could try and find different chemicals to dissolve a part of the atmosphere. We could raise the temperature until all the ice was melted creating water so we can live there.Actually, a NASA probe just reached Mars. It is called the Mars Surveyor. It will map the entire surface of Mars. After this we will have a better understanding of the Martian atmosphere and the polar ice caps. Melting this ice may not be worthwhile (say to a colonist living there) because scientists think that the ice caps may be made up of carbon dioxide ice.
December 29, 1997Ryo (Indonesia)I heard from the newspaper that three of Yemen's people claimed that Mars belonged to them, is it true?A planet cannot belong to anyone. But I am sure that human beings will go to Mars and then argue about who Mars belongs to. The first step, however, is for someone to actually set foot on Mars and bring something back. Then that person can say that whatever they brought back belongs to them.
December 8, 1997Audrey (Oregon, USA)Has a person ever stepped on Mars? Is Mars really hot?No one has stepped onto the planet Mars yet, but NASA expects to send a manned mission to Mars by the year 2020. Mars is definitely not hot--expect chilly temperatures around -63o F! Check out some of our previously asked Ask a Scientist questions to learn more about who will be first on Mars and what it would be like to live on Mars.
December 3, 1997Gary (Kentucky, USA)What is the planetary symbol for Mars?Here it is!

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