This January 19th, the planet Mercury reaches its greatest western elongation of 24.1 degrees from the Sun. This is the best time to view...

This January 19th, the planet Mercury reaches its greatest western elongation of 24.1 degrees from the Sun. This is the best time to view...

This January 19th, the planet Mercury reaches its greatest western elongation of 24.1 degrees from the Sun. This is the best time to view...

This January 19th, the planet Mercury reaches its greatest western elongation of 24.1 degrees from the Sun. This is the best time to view...

This January 19th, the planet Mercury reaches its greatest western elongation of 24.1 degrees from the Sun. This is the best time to view...

The Ursids is a minor meteor shower producing about 5-10 meteors per hour. It is produced by dust grains left behind by comet Tuttle,...

The Ursids is a minor meteor shower producing about 5-10 meteors per hour. It is produced by dust grains left behind by comet Tuttle,...

The Ursids is a minor meteor shower producing about 5-10 meteors per hour. It is produced by dust grains left behind by comet Tuttle,...

The Ursids is a minor meteor shower producing about 5-10 meteors per hour. It is produced by dust grains left behind by comet Tuttle,...

The Ursids is a minor meteor shower producing about 5-10 meteors per hour. It is produced by dust grains left behind by comet Tuttle,...

Jupiter’s Great Red Spot is a swirling anticyclonic storm that was previously large enough to fit three Earths inside.  However,...

Jupiter’s Great Red Spot is a swirling anticyclonic storm that was previously large enough to fit three Earths inside.  However,...

Jupiter’s Great Red Spot is a swirling anticyclonic storm that was previously large enough to fit three Earths inside.  However,...

Jupiter’s Great Red Spot is a swirling anticyclonic storm that was previously large enough to fit three Earths inside.  However,...

Jupiter’s Great Red Spot is a swirling anticyclonic storm that was previously large enough to fit three Earths inside.  However,...

Carl Sagan once proposed the idea of sailing through the cosmos via a solar-powered spacecraft.  This spaceship would use sunlight...

Carl Sagan once proposed the idea of sailing through the cosmos via a solar-powered spacecraft.  This spaceship would use sunlight...

Carl Sagan once proposed the idea of sailing through the cosmos via a solar-powered spacecraft.  This spaceship would use sunlight...

Carl Sagan once proposed the idea of sailing through the cosmos via a solar-powered spacecraft.  This spaceship would use sunlight...

Carl Sagan once proposed the idea of sailing through the cosmos via a solar-powered spacecraft.  This spaceship would use sunlight...