APOD: 2020 August 2 Б Two Worlds One Sun
1.08.2020

How different does sunset appear from Mars than from Earth? For comparison, two images of our common star were taken at sunset, one from Earth and one from Mars. These images were scaled to have same angular width and featured here side-by-side.

All the Water on Planet Earth
25.09.2022

How much of planet Earth is made of water? Very little, actually. Although oceans of water cover about 70 percent of Earth's surface, these oceans are shallow compared to the Earth's radius.

Firefall by Moonlight
6.05.2022

On certain dates in February, an elusive firefall can be spotted at sunset in Yosemite National Park, when water flows, the weather cooperates and the direction to the setting Sun is just right. Often...

Our Rotating Earth
30.06.2020

Has your world ever turned upside-down? It would happen every day if you stay fixed to the stars. Most time-lapse videos of the night sky show the stars and sky moving above a steady Earth.

A Message from Earth
2.05.2020

What are these Earthlings trying to tell us? The featured message was broadcast from Earth towards the globular star cluster M13 in 1974. During the dedication of the Arecibo Observatory - still one of the largest single radio telescopes in the world - a string of 1's and 0's representing the diagram was sent.

Earth and Moon through Saturns Rings
26.05.2020

What are those dots between Saturn's rings? Our Earth and Moon. Just over three years ago, because the Sun was temporarily blocked by the body of Saturn, the robotic Cassini spacecraft was able to look toward the inner Solar System.

Blue Marble Earth
5.02.2022

Welcome to planet Earth, the third planet from a star named the Sun. The Earth is shaped like a sphere and composed mostly of rock. Over 70 percent of the Earth's surface is water. The planet has a relatively thin atmosphere composed mostly of nitrogen and oxygen.

Cyclone Paths on Planet Earth
14.09.2021

Where on Earth do cyclones go? Known as hurricanes when in the Atlantic Ocean and typhoons when in the Pacific, the featured map shows the path of all major storms from 1985 through 2005. The map shows graphically that cyclones usually occur over water, which makes sense since evaporating warm water gives them energy.

The Dance of Venus and Earth
2.06.2020

Every time Venus passes the Earth, it shows the same face. This remarkable fact has been known for only about 50 years, ever since radio telescopes have been able to peer beneath Venus' thick clouds and track its slowly rotating surface. This inferior conjunction -- when Venus and Earth are the closest -- occurs today.

Methane Earth
11.02.2002

Can you help in reducing this blanket of methane gas that is warming up our Earth? Recent evidence holds that methane (CH₄) is second only to carbon dioxide (CO₂) in creating a warming greenhouse effect but is easier to control.