Mars in a Minute: What's Inside Mars?

In the echo method of estimating distnces, a radar signa was sent towards the Mars. If the echo was received after 8 minute 20 second, how far wat the Mars from the earth at that instant?

The atmospheric pressure on Mars is o.61 kPa. What is the pressure in mm Hg?

Phobo is a satellite of Mars. The period of its revolution around Mars is 0.319 days and its mean distance from Mars is 9.519xx10^(6)m . Assuming that the mass of Phobos is negligible compared to that of Mars, calculate the mass of Mars. Take G=6.668xx10^(-11)Nm^(-2)kg^(-2)

The mass of the earth is 9 times that of the mars. The radius of the earth twice that of the mars. The escape velocity of the earth is 12km//s . The escape velocity on the mars is ........ km//s

Mars is the nearest planet to the Earth.