Favorite photos for Earth Day 2019

Here’s a collection of wonderful photos from the EarthSky community in celebration of Earth Day 2019. Thank you all!

Sky chart of moon and planets

Watch for moon, Jupiter, Lyrid meteors

That bright moon in the sky before sunup will drown most of the ongoing Lyrid meteor shower from view. But the moon offers its own delights, sweeping past Jupiter in the next few mornings.

A reptile expert takes your burning dragon questions

As Game of Thrones returns for its final season, a herpetologist addresses some highly fictional dragon scenarios using real science.

Fly with the world’s fastest bird

When in its hunting dive, the Peregrine falcon is the fastest bird – in fact, the fastest animal – on Earth. Get a bird’s-eye view of the flight of this magnificent creature, in this video.

Sky chart of the Big Dipper, Arcturus and Spica

Follow the arc to Arcturus, drive a spike to Spica

If you only ever learn one star mnemonic, make it this one!

Use the Big Dipper to find the Little Dipper

Polaris – aka the North Star – marks the end of the Little Dipper’s handle. The 2 outer stars in the bowl of the Big Dipper always point to Polaris.

Two concentric rings around a star, seen by the ALMA telescope.

Here’s a solar system being born

Astronomers have spied 2 rings of dust around a young star, DM Tau. The image shows what our own solar system might have looked like as its planets were forming, 4.6 billion years ago.

What happened before the Big Bang?

How can we get an inkling of what existed before our universe began? Scientists at the Harvard-Smithsonian Center for Astrophysics suggest a way.

What exactly is twilight?

Twilight is that magical time between daylight and darkness. Astronomers, the experts on nighttime, recognize 3 twilights.

Flat, heart-shaped aspen leaves with thin, white aspen trunks in background.

How aspen leaves could save Mars rovers

Aspen trees – fondly called Quakies by some – have trembling, quivering leaves. Now those leaves have inspired an energy-harvesting mechanism that might rescue dust-laden rovers on Mars.