Our Planet

Locations of North Magnetic Pole since 1590

Arctic Sea Ice Maximum Extent on March 17, 2018.

An interesting map showing the locations of the North Magnetic Pole since 1590. The North Magnetic Pole moves over time due to magnetic changes in the Earth’s core. Today, the Geographic North Pole (the point in the Northern Hemisphere where the Earth’s axis of rotation meets its surface, the northernmost point on the Earth) differs from the North Magnetic Pole by about 500 kilometers (311 miles).

If a magnetic compass needle is allowed to rotate about a horizontal axis, it would point straight down at the North magnetic pole.

Terraforming Mars [here’s why it’s so hard]

If we want to colonize Mars in the future, it would be better for us to terraform the planet, in order to make the colonization process safer and sustainable. But, terraforming Mars will be a real challenge for humanity.

InSight Lander Takes a Selfie on Mars

NASA’s InSight lander takes a selfie – this is what it looks like on Mars (InSight is the abbreviation for Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport). With its solar panels deployed, InSight is about the size of a small bus.

How many great minds does it take to invent a telescope?

Isaac Newton's reflecting telescope of 1671

On 11 January 1672, the Fellows of the British Royal Society were treated to a demonstration of Isaac Newton’s reflecting telescope, which formed images with mirrors rather than with the lenses that had been used since the time of Galileo. Afterward, the fellows hailed Newton as the inventor of this marvelous new instrument, an attribution that sticks to the present.

However, this linear historical account obscures a far more interesting, convoluted story. Newton’s claim was immediately challenged on behalf of two other contenders, James Gregory, and Laurent Cassegrain. More confounding, the earliest known concept of using a curved mirror to focus light predated Newton by more than 1,500 years; the final realisation of a practical reflecting telescope post-dated him by more than a half-century.

Solar Panels work by absorbing LIGHT from the sun, not heat

Ignorance is a very, very bad thing. Last week, as North America suffering from extreme cold weather because of a phenomenon called “polar vortex“, Jim Hoft, founder of the American far-right news and opinion website The Gateway Pundit has tweeted that: “It’s a bit cold outside this morning in middle America… Aren’t you glad you aren’t heating your home with a solar panel like nitwit socialist @AOC is demanding?” (@AOC is the American politician and activist Alexandria Ocasio-Cortez here.) What Jim Hoft says is flat-out wrong. Solar panels DO work in the cold. They work by absorbing LIGHT from the sun, not heat.

Snow cover of Earth between Mar. 2000 and Dec. 2018

Here is a quick summary of the Earth’s snow cover between March 2000 and December 2018. These snow cover maps are made from observations collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite.

Polar Vortex is the reason why the winter is so harsh in North America

The polar vortex is a large area of low pressure and cold air surrounding the Earth’s north and south poles. It is the reason why extreme winter conditions are bringing record-breaking cold temperatures to parts of North America.

Earth and Moon: a 1992 Family Portrait

Earth and Moon from the Galileo spacecraft (1992)

On December 16, 1992, eight days after its final encounter with Earth, NASA’s Galileo spacecraft looked back and captured this remarkable view of Earth and the moon.

Moon Drawings of Galileo Galilei (1609)

Galileo Galilei's Moon Drawings (cropped)

Italian astronomer, physicist, engineer, and polymath Galileo Galilei’s (15 February 1564 – 8 January 1642) moon drawings. These were the first realistic images of the Moon, due to Galileo’s training in art and an understanding of chiaroscuro (a technique for shading light and dark) he understood that the shadows he was seeing were actually mountains and craters.

The crescent Earth rises above the lunar horizon

Crescent Earth rises above the lunar horizon - Apollo 17 photo

An amazing NASA photo: the crescent Earth rises above the lunar horizon in this spectacular photograph taken from the Apollo 17 spacecraft in lunar orbit during the final lunar landing mission in the Apollo program.