Path of the solar eclipse on December 14, 2020.


A South American Total Eclipse

The Moon’s shadow visits Chile and Argentina again. If you can't be there, watch online!

Eclipses & Occultations

2017 Eclipse Resources

With all the interest in August’s sky spectacular, it’s no surprise that you can find lots of great information about solar eclipses. Here are some favorite resources chosen by the editors of Sky & Telescope magazine: Books About Eclipses In the Shadow of the Moon: The Science, Magic, and Mystery…

Path of February 2017 annular eclipse

Celestial News & Events

February 26th's Annular Solar Eclipse in 2017

Die-hard eclipse chasers have journeyed to the Southern Hemisphere to catch a short but dramatically thin "ring" eclipse of the Sun this weekend.

Penumbral eclipse series from 2012

Celestial News & Events

February's Deep Penumbral Lunar Eclipse

North American observers can watch the Moon flirt with Earth’s shadow on the evening of February 10th.

Total Solar Eclipse over Easter Island

Celestial News & Events

Solar and Lunar Eclipses in 2017

It won't be a great year for lunar eclipses, with a deep penumbral event on February 11th and a partial on August 7th. But an annular solar eclipse is observable from the Southern Hemisphere on February 26th, and a total solar eclipse crosses the continental U.S. on August 21st.

Path of 2017 total solar eclipse

Celestial News & Events

Planning for America's Great American Eclipse in August 2017

Dozens of solar specialists are coordinating outreach activities for a coast-to-coast total solar eclipse that's only two years away.


Astronomy Questions & Answers

When will the last total solar eclipse occur?

With the Moon slowly receding from Earth, there will come a time when it no longer has sufficient angular size to cover the Sun completely. When will the last total solar eclipse occur? When the Moon’s at its closest and biggest and it can no longer cover the Sun at…

solar prominence

Hobby-based Q&A

Why do you need a hydrogen-alpha filter to see solar prominences?

If I can see solar prominences with the naked eye during a total eclipse, why do I need a hydrogen-alpha filter to see them at other times? During a total eclipse the Moon completely blocks the Sun’s photosphere, or visible “surface,” allowing prominences (and the corona) to shine in all…

Weird moon Prometheus

Science-based Q&A

Is there another planet besides Earth whose moon(s) would fit perfectly over the Sun?

It is amazing when you think about the coincidence of the Sun being 400 times bigger than our Moon, yet 400 times farther away, producing an almost perfect fit for a total solar eclipse. Is there another planet whose moon(s) would fit perfectly over the Sun, or are we just…

Venus Ring of Light

Astronomy Questions & Answers

How did early astronomers calculate accurate solar system positions?

In the pre-computer age, say 50 years ago and back, how did astronomers calculate accurate positions of the Sun, Moon, and planets for predicting an eclipse or a transit of Venus? They did it by hand, with the help of numerical tables. These weren’t the trigonometric and logarithmic tables you…

Mercury near the Sun's limb

Hobby-based Q&A

Will Mercury and Venus ever transit the Sun simultaneously?

Will Mercury and Venus ever transit the Sun simultaneously? Yes, but this will not happen until AD 69,163. A transit can take place only when Mercury or Venus is near an ascending or descending node, meaning a crossing point of its orbit on the plane of the ecliptic. For this…

Mercury near the Sun's limb

Astronomy Questions & Answers

How can I polar align in the daytime?

I want to see a planetary transit. How can I polar align my telescope in the daytime? One good way is to use the Sun. Carefully level your mount with a bubble level and set the polar axis to the latitude of your site. Hang a weighted string from the…