Astronomical Event Information and Upcoming Dates
Upcoming Lunar Eclipses | Upcoming Solar Eclipses | Solar Eclipse Safety | Planetary Alignments | Community Stargazing
Lunar Eclipses
Lunar eclipses occur at the full moon phase. When Earth is positioned precisely between the Moon and Sun, Earth’s shadow falls upon the surface of the Moon, dimming it and sometimes turning the lunar surface a striking red over the course of a few hours. Each lunar eclipse is visible from half of Earth.
Types of Lunar Eclipses
Total lunar eclipse
The Moon moves into the inner part of Earth’s shadow, or the umbra. Some of the sunlight passing through Earth’s atmosphere reaches the Moon’s surface, lighting it dimly. Colors with shorter wavelengths ― the blues and violets ― scatter more easily than colors with longer wavelengths, like red and orange. Because these longer wavelengths make it through Earth’s atmosphere, and the shorter wavelengths have scattered away, the Moon appears orangish or reddish during a lunar eclipse. The more dust or clouds in Earth’s atmosphere during the eclipse, the redder the Moon appears.
Partial lunar eclipse
An imperfect alignment of Sun, Earth and Moon results in the Moon passing through only part of Earth’s umbra. The shadow grows and then recedes without ever entirely covering the Moon.
Penumbral eclipse
If you don’t know this one is happening, you might miss it. The Moon travels through Earth’s penumbra, or the faint outer part of its shadow. The Moon dims so slightly that it can be difficult to notice.
Upcoming Lunar Eclipses
Solar Eclipses
Solar eclipses happen only at the new moon phase, when the Moon is between Earth and the Sun. During a solar eclipse, the Moon casts a shadow on Earth, and blocks or partially blocks our view of the Sun. Though solar eclipses happen as often as lunar eclipses, they are visible from such a small area of Earth each time that it’s much rarer to encounter one.
During a solar eclipse, the Moon’s shadow on Earth’s surface is only about 300 miles (480 km) wide. The shadow consists of two parts, the umbra, where the Sun is completely blocked, and the penumbra, where the Sun is partially obscured. People in the umbra will see a total eclipse, while people in the penumbra will see a partial eclipse. Though the shadow is narrow and the total eclipse lasts for only minutes, our planet rotates fast enough to bring the shadow a third of the way around Earth’s surface before the Moon moves out of alignment with the Sun.
Upcoming Solar Eclipses
SOLAR ECLIPSE SAFETY
Safety is the number one priority when viewing a total or partial solar eclipse.
Safe Solar Glasses and Eclipse Activity Kits can be found, among others, on the Astronomical Society of the Pacific website at https://myasp.astrosociety.org/eclipse-shop
During a partial solar eclipse, it is not safe to look directly at the Sun without specialized eye protection for solar viewing. Viewing any part of the bright Sun through a camera lens, binoculars, or a telescope without a special-purpose solar filter secured over the front of the optics, will instantly cause severe eye injury.
Be sure you're familiar with these safety guidelines for solar viewing at:
PLANETARY ALIGNMENTS
On most nights, weather permitting, you can spot at least one bright planet in the night sky. While two or three planets are commonly visible in the hours around sunset, occasionally four or five bright planets can be seen simultaneously with the naked eye. These events, often called "planet parades" or "planetary alignments," can generate significant public interest. Though not exceedingly rare, they're worth observing since they don't happen every year.
As the planets of our solar system orbit the Sun, they occasionally line up in space in events called oppositions and conjunctions. A planetary alignment can also refer to apparent lineups in our sky with other planets, the Moon, or bright stars. The planets of our solar system always appear along a line on the sky. This line, referred to as the ecliptic, represents the plane in which the planets orbit, seen from our position within the plane itself.
When it comes to this second type of planetary alignment, it's important to understand that planets always appear along a line or arc across the sky. This occurs because the planets orbit our Sun in a relatively flat, disc-shaped plane. From Earth, we're looking into that solar system plane from within. We see the racetrack of the planets from the perspective of one of the racers ourselves. When viewed edge-on, this disc appears as a line, which we call the ecliptic or ecliptic plane.
So, while planet alignment itself isn't unusual, what makes these events special is the opportunity to observe multiple planets simultaneously with the naked eye.
Community stargazing WITH MCAULIFFE CENTER STAFF
Once a month, use telescopes to observe the night sky. McAuliffe Center staff are available to answer your questions about telescopes and our Universe. Check for upcoming Community Stargazing events at cm-center.org/events
All Text and Photo Credit to NASA