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






Science Quote

'The strength and weakness of physicists is that we believe in what we can measure. And if we can't measure it, then we say it probably doesn't exist. And that closes us off to an enormous amount of phenomena that we may not be able to measure because they only happened once. For example, the Big Bang. ... That's one reason why they scoffed at higher dimensions for so many years. Now we realize that there's no alternative... '

Michio Kaku
(1947-)
Science Sidebar | Science Education Articles
Cool Summer Science Projects

Why not make science a part of your family’s summer? Perhaps you can set aside one day a week for outdoor projects—maybe Mad Scientist Monday or Scientific Saturday? Here are a few ideas to help get you started. Continue reading ...

10 Ways to Keep Your Kids Interested In Science

Young children are natural scientists: they ask questions, pick up sticks and bugs outside, and are curious about the world around them. But as they get a bit older, many kids gradually lose their interest in science. They might see it as just another task at school, something that doesn't apply to their lives. Of course nothing could be further from the truth, so here are ten ways you can remind your kids that science is everywhere. Most of these are fun for adults, too! Continue reading ...

Top Selling

Here are our physics & astronomy bestsellers:
Magnetic Levitator - Classic
3D Magnetic Field Tube
Revolving Multi-Color Fiberoptic Light
KonusScience 5 Way Microscope Kit
Periscope
Tin Can Robot 4M Kit
Mini Plasma Ball
Solar Radiometer
Wood Grain Newtons Cradle
12 inch Galileo Thermometer

Sponsors

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