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Articles about Astronomy (91)

What is a Supermoon?

A supermoon is when a full Moon or new Moon coincides with the Moon's closest approach to the Earth. more

September Equinox

The Sun shines directly at the Equator on the September equinox and the length of day and night is nearly equal, but not quite. more

Perseid Meteor Shower

The 2016 Perseid meteor shower will peak on August 12 and 13. A waxing gibbous Moon will make it harder for observers to watch the meteor shower. more

December Solstice

The December solstice is also known as the summer solstice in the Southern Hemisphere and the winter solstice in the Northern Hemisphere. more

When is Fall Equinox?

The fall (autumnal) equinox in the Northern Hemisphere is in September. In the Southern Hemisphere, it's in March. more

What is June Solstice?

The June solstice is the longest day of the year in the Northern Hemisphere & the shortest day in the Southern Hemisphere. more

When is Spring Equinox?

The Vernal (Spring) Equinox in the Northern Hemisphere is in March. In the Southern Hemisphere, it's in September. more

About Moon phases

There are 4 primary phases of the Moon - new, first quarter, full and third quarter, and 4 intermediate phases - waxing crescent and gibbous, and waning gibbous and crescent. more

March Equinox

The March equinox around March 20-21 is the spring (vernal) equinox in the Northern Hemisphere and fall (autumnal) in the south. Night and day are nearly the same length. more

Meteor Showers

Dates and tips on how and where to view Meteor Showers all over the world. more

Equinox: Equal Day & Night?

Equinoxes don't have exactly 12 hours of day and night all over the world, like many believe. Such days do happen, but depend on the latitude of your city. more

What Is a Micromoon?

A Micromoon is the name given to a full or new Moon when the Moon is farthest from the Earth, at apogee. more

Solar Eclipses in History

Solar eclipses were historically viewed as omens that bring about death and destruction and people in many ancient civilizations tried their best to understand and predict them. more

What are Moonbows?

Moonbows occur when the Moon’s light is reflected and refracted off water droplets in the air. more

Annular Solar Eclipse

An annular solar eclipse occurs when the Moon moves in front of the Sun but does not cover it completely. more

2016 Orionid Meteor Shower

In 2016, the Orionid meteor shower will be visible from October 2 to November 7. The shower is expected to peak on the night of October 20 and early morning of October 21. more

Partial Solar Eclipse

More common than a total solar eclipse, a partial solar eclipse happens when the Moon only partially covers the Sun. more

2016 Geminids Meteor Shower

The Geminids meteor shower can be seen from December 4-17. In 2016, the shower will reach its maximum around December 13. Find out where, when and how you can see it. more

2017 Quadrantids Meteor Shower

The 2017 Quadrantids meteor shower is expected to peak on January 4, 2017. Quadrantids, the first major shower of the year is best viewed from locations in the Northern Hemisphere. more

Make a Pinhole Projector

DIY: Make a simple pinhole projector using two pieces of card or paper to safely watch a projection of a solar eclipse. more

What are Comets?

Comets are small celestial bodies that orbit the Sun. Made of dust and ice, they are remnants of Solar System's formation. more

June 5-6, 2012: Transit of Venus

The 2012 Venus transit was the last chance to see this phenomenon for over 100 years. Mercury transits happen more often, the next one in May 2016. more

Asteroid to fly by Earth

At 7:24 PM UTC (19:24) on Friday, February 15, 2013, an asteroid called 2012 DA14, will come close to the Earth, closer than any other asteroid of similar size has ever come in recorded history. more

Zodiacal lights

Also known as false dawn, zodiacal lights are rare optical phenomena that occur around sunset and sunrise in early spring and late fall. more

3 comets in 2013

Three comets - comet ISON, comet Lovejoy and comet Encke will grace the winter skies in 2013. more

2013: Year of comets

2013 is going to be a good year for comet watchers, with at least 3 comets that may be visible without the aid of sophisticated equipment. more

What is Local Mean Time (LMT)?

Use a sundial to determine the time of day and you will probably be off by a few minutes. That's where LMT comes into play. How is it measured and what is it used for? more

What's a Blood Moon?

Blood Moon is sometimes used to describe 4 total lunar eclipses in a row. When the Earth casts its shadow on a full Moon and eclipses it, the Moon may get a red glow. more

11 Facts: Total Lunar Eclipse

The Sept 27/ 28, 2015 Total Lunar Eclipse is the final eclipse in a series of 4 total eclipses of the Moon called eclipses of the Blood Moon. more

Eclipse Magnitude

Eclipse magnitude is a number that astronomers associate with solar or lunar eclipses. What does it mean? more

Mercury Transit

Local time for Mercury transit May 9 / May 10, 2016. Visible from most of the world. Will you be able to see it? Map of path and animation. more

What's a Solar Eclipse?

Solar eclipses happen when the Moon moves between Sun and Earth, blocking the Sun's rays and casting a shadow on Earth. more

Solar Eclipse Myths

The solar eclipse has inspired many mythical stories and influenced human behavior. Even today, eclipses of the Sun are considered bad omens in many cultures. more

Asteroid 2004 BL86 to Fly By Earth

On Monday, January 26, 2015 asteroid 2004 BL86 will fly by at only 3 times the distance of the Moon from the Earth. It will be the largest celestial body to come this close to Earth until 2027. more

What is Earthshine?

Earthshine refers to the phenomenon when light from the Earth illuminates the Moon. Find out when you can see it. more

Equation of Time

Why doesn't the year's earliest sunset occur on the Winter Solstice, even though it is the shortest day of the year in terms of daylight? more

Midnight Sun

Midnight Sun, or Polar Day, means that at least a sliver of the Sun's disk is visible above the horizon 24 hours of the day. more

Earth's Orbit & Solstice

The Earth's closest approach to the Sun 2 weeks after the December solstice is a coincidence and has no special significance. more

Venus - Jupiter - Mars Conjunction

From time to time, some of the planets in our solar system are in conjunction and become visible together in the sky. Venus, Jupiter, Mars, and Mercury have all been visible in the early mornings of October 2015. more

What are Polar Nights?

A Polar Night is a night that lasts for at least 24 hours. It's the opposite of Midnight Sun / Polar Day. more

What Causes Seasons?

Seasons happen because the Earth's axis is tilted and different parts of the planet point toward or away from the Sun at different times of the year. more

Solar analemma

An Analemma is a graph or plot that shows the position of the sun in the sky at a single location and at the same time of the day throughout a year as measured by a sundial. more

Timekeeping by Stars

Out and about at night without a watch or a smartphone readily available? If you are in the Northern Hemisphere use the Big Dipper and the North Star to tell the time. more

A Year Is Never 365 Days

The definition of a tropical year, also known as a solar year, astronomical year, or equinoctial year, is the time it takes the Earth to complete a full orbit around the Sun, and it is approximately 365.242189 days long. more

What is a Black Moon?

It can be the 3rd New Moon in a season of 4 New Moons or the second New Moon in a calendar month. The next Black Moon is in October 2016. more

Is a Blue Moon blue?

A Blue Moon is a type of a full Moon. It can also be a rare Moon that looks blue due to atmospheric dust particles. more

Full Moon names

Find out Full Moon names and their meanings by month and seasons, common in many North American cultures. more

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