Question

Why is Venus the hottest planet even though Mercury is closer to the sun?

Asked by: Akil

Answer

Mercury is closest to the sun, this is true. However, because of its proximity to the sun it lacks an atmosphere. Mercury's gaseous molecules reached escape velocity long ago and the atmosphere was 'burned off' leaving a vacant wasteland of rock with a similar surface to the earth's moon. There is nothing to hold in solar radiation, thus is flies out into space.

Venus Venus is a different story. Its atmosphere is primarily composed of carbon dioxide - the primary green house gas -, which acts like a one-way door. The solar heat enters, but it cannot leave. Thus, an oven is created. This is why Venus has no water. Pictures suggest that Venus once had an aqueous environment, but because of climatic changes and intense heat.... it evaporated.

Also, because of an overactive core, Venus seems to recreate its continents every X years. So, we do not expect to find fossils or many bacteria.

Answered by: Joel Levy, State University of New York - Albany

Search

Loading



Sponsors

USC University of Southern California Dornsife College Physics and Astronomy Department McMaster University Physics and Astronomy Department

Science Quote

'Imagination disposes of everything; it creates beauty, justice, and happiness, which is everything in this world.'

Blaise Pascal
(1623-1662)

Deal of the Day

Image of RC Flying Saucer. Click on this image for more info. RC Flying Saucer
Regular Price: $29.99
Today's Price: $14.00
Have hours of fun with this colorful remote controlled flying saucer! Buy it now! Deal ends at midnight!

Top Selling

Here are our physics & astronomy bestsellers:
Mini Plasma Ball
Slide Making Kit
The Ultimate Geek Pen
Top Secret - Spinning Top
Solar Radiometer
Thermodynamic Drinking Bird
Wood Grain Newtons Cradle
Deluxe 3D Mirascope
Periscope
3D Magnetic Field Tube