Astronomy

In a year, the earth completes one orbit around the sun. Equinox is the two times of the year when the sun crosses the plane of the earth's equator and when the length of day and night is just...

Constellations are groupings of stars that form a pattern to an observer on Earth. There are 88 constellations, most of them named in ancient times by civilizations such as the Greeks and the...

Polaris is the name of a star much more commonly called the North Star. Polaris lies less than one degree from the celestial North Pole, an imaginary point directly over the Earth's own North...

The constellation Taurus the Bull is one of the largest and best-known of all of the constellations in the night sky. As a zodiac constellation, Taurus has the sun, moon and all of the planets...

Setting up an Orion StarBlast 4.5 does not require a significant amount of expertise from first-time telescope owners. The StarBlast is a reflector telescope, which is widely preferred over...

There was a time when people traveled to places so far and so strange -- America, for example -- that there were no lands to mark on the journey but rather days and days of sea. Still, explorers...

The eight phases of the moon represent the percentage of the moon that appears illuminated from the Earth. Earth's gravity pulls on the moon and keeps it in orbit. As the moon orbits the Earth,...

Until the time of Nicholas Copernicus, the accepted school of thought was that the Earth was the center of the solar system. Yet it wasn't until Johannes Kepler published "The New Astronomy" in...

Neptune is the eighth planet from the Sun and is a much larger world than Earth. Neptune is what astronomers classify as a "gas giant" and has a very different chemical makeup than the Earth...

As the moon orbits around Earth, parts of the moon reflect sunlight. In the night sky, we observe these moon phases from our different locations on Earth. Because the moon changes from new, to...

There are more macaroni penguins than any other type, with the International Penguins Conservation Work Group estimating there are nine million breeding pairs and the Antarctic Connection website...

Saturn is a fascinating planet that has great mass, rings that revolve around it and as many as 60 moons trapped in its gravitational field. Saturn, 10 times further from the Sun than Earth is,...

Knowing how to find and identify the planets and stars can be fascinating for adults and children alike, and educational too. Pass the evening stargazing for inexpensive entertainment. Every...

The Big Dipper is one of the most ancient star groupings --- so ancient that the actual origin of its name, and the time when early man first became aware of it, is a mystery.

The phases of the moon have been observed and recorded by cultures throughout the world for thousands of years. The prominence of the moon in the sky as the second brightest object (after the sun)...

Planet Earth is surrounded by four distinct layers of atmosphere, with each layer being enveloped by another. The layers, from nearest to the planet to the farthest, begin with the troposphere,...

Scientists attribute the hot conditions on Venus to the greenhouse effect, or the trapping of heat between the atmosphere and the surface. Studying the greenhouse effect on Venus reveals why the...

The seven most prominent stars in the constellation Ursa Major form a familiar star pattern, which astronomers term an asterism. While other cultures have gazed toward this group of stars and...

If you want to find a certain star at a specific day and time, or simply want to identify the constellations in the night sky, you'll need a paper star locator. This square shows the different...

From lighting houses and running equipment to purchasing supplies and playing sports, modern society relies on readily-available, consistent and adequate levels of electrical power. However, solar...

Astronomers often utilize the Big Dipper, a large and recognizable portion of the Ursa Major constellation, as a sort of road map to locate other stars and constellations. By drawing imaginary...

Every year, over 2,000 satellites are launched into orbit around Earth. Many of these satellites will enter into geostationary orbit above the Earth's equator. Satellites in geostationary orbit...

On June 11, 2008, NASA launched the Fermi Gamma-ray telescope. This telescope is able to send detailed, real-time data of the universe back to Earth. But what is a gamma-ray telescope, and what is...

For observers who live at or above 30 degrees north in terms of latitude, the asterism known as the Big Dipper is visible throughout the entire night year round. However, the Big Dipper will be at...

The best way to view the Perseid Meteor Showers, or any meteor shower, is to lay down so that there is a full view of the sky. Get the best view of a meteor shower with help from an...

A total lunar eclipse occurs when the moon passes through the Earth's shadow and is best viewed with the naked eye or with a pair of binoculars. Avoid using a telescope when viewing a lunar...

Setting circles are used to tell where the telescope is pointed in the sky. Use setting circles by reading ascension and declination with help from an astrophotographer in this free video on...

Remembering the planets in order is as easy as remembering the mnemonic device of saying, "My Very Eager Mother Just Served Us Nine Pizzas." Remember the planets, with or without Pluto, in order...

The Big Dipper and the Little Dipper are asterisms that are a part of the constellations Ursa Major and Ursa Minor, respectively. Look for the Big Dipper and the Little Dipper in the northern sky...

The easiest way to focus a telescope is by moving the eye piece and changing the spacing between optical elements. Find out different ways to focus a telescope, such as moving the mirrors...

Orion is one of the most easily recognizable constellations due to the three stars that form the belt of Orion. Look for Orion almost due East in the fall with help from an astrophotographer in...

When taking care of a telescope, it's important to have covers that keep dust off of the optical surfaces. Keep the eye piece of a telescope in a case with help from an astrophotographer in this...

The key in buying a telescope is aperture size and making sure that the opening of the telescope is as large as possible. Discover how the ability of a telescope to gather light results in a...

Saturn, the second largest planet in our solar system, is the sixth planet from the sun. Saturn is most famous for its large rings made up of ice particles that surround the planet.

The orbit of the Earth is circular but it is not a perfectly round circle. The orbit is somewhat elliptical, with the Earth being closer to the Sun in January and furthest from it in July.

Ursa Major, a constellation that represents a bear and contains the famous Big Dipper star system, seems to change its location during the course of the evening. This is due to the rotation of the...

Two of the most recognizable star patterns in the night sky are the belt of Orion and the Big Dipper. These two "asterisms" are in separate constellations.

The planets inside of Earth's orbit, Mercury and Venus, are so near to the Sun that they are often only visible close to sunset and sunrise--especially Mercury. The planets outside of Earth's...

There are many reasons you might want to find stars in the sky. Perhaps you are taking a class on astronomy. Maybe you are on a trip to a new place and looking for an interesting activity. Or...

Ursa Major is one of the most recognizable constellations in the sky, even though most people do not know it by that name. A circumpolar constellation, Ursa Major is found by looking to the north...

The constellation of Cancer is a difficult one to recognize when you are looking right at it, so imagine how hard it is to find if you do not know anything about it. While this star grouping...

There are four major phases of a moon, each of which occurs once in a lunar month (29.5 days). (See Reference 1). The first phase is called a "new moon," which occurs when the moon's unilluminated...

Saturn is one of the few planets in the solar system that has rings. But why aren't there more ringed planets and why doesn't Earth have a ring? There are several elements, including size and...

When scientists struggled to describe the vast distances between celestial objects, they came up with the concept of the light-year. Rather than a measurement of time, the light-year is a...

On a night when the temperature falls rapidly and the air is calm, dew will form on telescope mirrors and lenses, blocking or impeding light. A good way to prevent the formation of dew on...

Before World War II, there was a considerable telescope-making population around the world. Today, would-be observers usually just buy a telescope, but a few still find enjoyment in making their...

Plastic lenses are most often found on astronomical telescopes, the oculars (eyepieces) used with telescopes and in binoculars; however, they may be found in a variety of optical applications. In...

A simple to build and use, hand-held solar radio telescope can be made with a few dollars worth of parts and an hours worth of time. Will it work as well as Jodie Foster's large radio telescope...

The constellation of Cancer the Crab is one star grouping with much mythology associated with it. This is quite a distinction for a dim constellation which only those who study the stars can...