national geographic stars and constellations

national geographic stars and constellations插图

How do constellations get their names?

Many are named for mythical figures, such as Cassiopeia and Orion the Hunter. Others are named for the animals they resemble, such as Ursa Minor (Little Bear) and Canus Major (Big Dog). Today astronomers use constellations as guideposts for naming newly discovered stars. Constellations also continue to serve as navigational tools.

What are constellations used for Today?

Today astronomers use constellations as guideposts for naming newly discovered stars. Constellations also continue to serve as navigational tools. In the Southern Hemisphere, for example, the famous Southern Cross constellation is used as a point of orientation. Meanwhile people in the north may rely on Polaris, or the North Star, for direction.

How many constellations are there in the universe?

While cultures around the world have given names to the most prominent star patterns, astronomers today recognize 88 modern constellations largely based on classical Greek teachings. Of these, the constellations of the zodiac are perhaps the most well-known.

What constellations are not visible in the southern hemisphere?

The most familiar constellation in the Southern Hemisphere, for instance, is the Southern Cross. The stars in this constellation are never visible in the Northern Hemisphere above the tropics. The Big Dipper, a familiar constellation in the Northern Hemisphere, is not visible in the Southern Hemisphere.

How many stars are there in the universe?

Stars are huge celestial bodies made mostly of hydrogen and helium that produce light and heat from the churning nuclear forges inside their cores. Aside from our sun, the dots of light we see in the sky are all light-years from Earth. They are the building blocks of galaxies, of which there are billions in the universe. It’s impossible to know how many stars exist, but astronomers estimate that in our Milky Way galaxy alone, there are about 300 billion.

Why does a protostar spin faster?

As a protostar gets smaller, it spins faster because of the conservation of angular momentum —the same principle that causes a spinning ice skater to accelerate when she pulls in her arms. Increasing pressure creates rising temperatures, and during this time, a star enters what is known as the relatively brief T Tauri phase.

What is the name of the cloud that gives birth to a star?

Birth takes place inside hydrogen-based dust clouds called nebulae. Over the course of thousands of years, gravity causes pockets of dense matter inside the nebula to collapse under their own weight. One of these contracting masses of gas, known as a protostar, represents a star’s nascent phase. Because the dust in the nebulae obscures them, protostars can be difficult for astronomers to detect.

What is the main sequence of stars?

Most of the stars in our galaxy, including the sun, are categorized as main sequence stars. They exist in a stable state of nuclear fusion, converting hydrogen to helium and radiating x-rays. This process emits an enormous amount of energy, keeping the star hot and shining brightly.

Why are constellations important to ancient cultures?

Ancient cultures looked to the sky for all sorts of reasons. By identifying different configurations of stars—known as constell ations—and tracking their movements, they could follow the seasons for farming as well as chart courses across the seas. There are dozens of constellations. Many are named for mythical figures, such as Cassiopeia and Orion the Hunter. Others are named for the animals they resemble, such as Ursa Minor (Little Bear) and Canus Major (Big Dog).

How long does the Sun stay in its main sequence?

Now around 4.6 billion years old, Earth’s sun is considered an average-size yellow dwarf star, and astronomers predict it will remain in its main sequence stage for several billion more years.

Why are supernovae used as candles?

Because certain supernovae have a predictable pattern of destruction and resulting luminosity, astronomers are able to use them as “standard candles,” or astronomical measuring tools, to help them measure distances in the universe and calculate its rate of expansion.

What do explorers do?

National Geographic Explorers take risks, stretch boundaries, and conduct inquiries to make a positive impact on the world. Through their curiosity, problem solving skills, and expert knowledge they help us better understand our natural world, its people, and its cultures. In this time when we all have to chart the unknown from our homes, we have a chance, perhaps even the responsibility, to be explorers. Successful explorers prepare before an expedition, then reflect on what they learn afterward, and share it with others. This curated collection of resources shows National Geographic Explorers in action observing natural phenomena and collaborating with others to achieve their goals.

What is the name of the group of planets that orbit a large star?

A star system is a group of planets, meteors, or other objects that orbit a large star. While there are many star systems, including at least 200 billion other stars in our galaxy, there is only one solar system. That’s because our sun is known by its Latin name, Sol. The solar system includes everything that is gravitationally drawn into the sun’s orbit. Astronomers have discovered there are many other large stars within our galaxy, the Milky Way. Use these resources to teach students about the objects and relationships within our solar system.

What is a large object that orbits a star?

A planet is a large object that orbits a star

How many women are in STEM?

While nearly half of all humans are women, fewer than 30 percent are among the world’s Science, Technology, Engineering, and Mathematics (STEM) professionals. The resources in this collection show how women around the world are defying these limitations and pursuing STEM careers to make a difference in their communities.

Who is Munazza Alam?

Astrophysist Munazza Alam is on the hunt for an Earth-twin, a planet with conditions similar enough to ours that it may even contain life. But to do so, she needs to look right into the heart of stars well beyond our solar system.

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How long did it take for a mystery object to blot out a giant star?

Mystery object blotted out a giant star for 200 days

Which planets will touch on the winter solstice?

In rare sky show, Jupiter and Saturn will nearly ‘touch’ on the winter solstice

Which black hole is closest to Earth?

Newfound black hole may be the closest to Earth

Is the radio telescope in Puerto Rico at risk of collapsing?

Iconic radio telescope in Puerto Rico is at risk of collapsing

What is a star party?

Star parties are gatherings where professional and amateur astronomers set up their telescopes and invite people to come learn about the night sky. Getting away from light pollution, or artificial skylight from buildings for example, helps stargazers see objects in the sky much better.

Why is it important to get away from light pollution?

Getting away from light pollution helps stargazers see objects in the sky much better.

How many people gather in the dark on a hillside in Virginia?

More than a hundred adults and kids gather on a cold evening, chattering excitedly as they stand in the dark on a Virginia hillside. The odd thing is, no one has turned on a flashlight, and no streetlights or house lights wink on around them.

What does O’Brien say about star parties?

O’Brien says you can have your own star party at home and learn a lot just by paying attention to what’s happening up above. “Watch the sky as the seasons pass, and you will see that it changes,” he says.

How is radio navigation similar to celestial navigation?

The navigator can tune into a radio station and use an antenna to find the direction of the broadcasting radio antenna.

What is the difference between longitude and latitude?

Understanding latitude and longitude are very important in navigation. Latitude is a north-south position measured from the Earth’s Equator and longitude is an east-west position measured from the prime meridian. There are many different navigation techniques.

What is celestial navigation?

For sailors, celestial navigation is a step up from dead reckoning. This technique uses the stars, moon, sun, and horizon to calculate position. It is very useful on the open ocean, where there are no landmarks.

Why is the mouth of the Columbia known as the "Graveyard of the Pacific"?

Because so many ships and sailors have been lost in the turbulent waters , the mouth of the Columbia is known as the "Graveyard of the Pacific.". Polynesian Navigation. The ancient Polynesians navigated hundreds of thousands of miles of the Pacific Ocean using a combination of celestial navigation and piloting.

How many satellites are there in the world?

It now includes about 24 satellites that orbit the Earth and send radio signals from space. The system works much like radio navigation. A GPS device receives a signal from the satellites, and it calculates position based on the time it takes for the signal to transmit and the exact position of the satellites.

How long have people been using navigation techniques?

There are many different navigation techniques. People have been using some of them for thousands of years.

What is the purpose of a compass?

Compass es, which indicate direction relative to the Earth’s magnetic poles, are used in navigation on land, at sea, and in the air. Compasses were being used for navigation by the 1100s, and are still the most familiar navigational tools in the world. Dead Reckoning.

How to observe Jupiter with kids?

As a fun experiment, have kids hold their binoculars steady while watching Jupiter; they’ll observe its four largest moons, first seen by Italian astronomer Galileo over 400 years ago using the newly invented telescope. Then on a piece of paper, ask them to draw the positions of each moon beside Jupiter.

What is the best way to introduce kids to astronomy?

Stargazing is an accessible activity for families—and a great excuse to introduce kids to astronomy. ( Explore National Geographic Kids’ space hub .) For starters, parents can teach their children about the basics of the cosmos, such as major constellations, planets, and the moon.

What is the brightest object in the sky?

In April and May, viewers across the world can look toward the western sky at dusk see a startlingly vivid Venus, the brightest object in the sky. Meanwhile if you look toward the east an hour before your local sunrise, you’ll see the planetary trio of Mars, Jupiter, and Saturn.

What is the name of the star that pours its contents onto Earth?

The next clear night this spring, look high overhead in the northern sky and spot the dipper’s “bowl” appearing to pour its contents onto Earth. Use the stars that mark the outer edge of the bowl to draw an imaginary line toward the horizon until you hit the next brightest star. That’s Polaris (aka the North Star), part of the Ursa Minor (“little bear”) constellation.

What are the two types of telescopes?

When it comes to family telescopes, the two main types are lens-based refractors and reflectors that focus starlight using mirrors . The main features to look for in a scope are a high-quality lens, a rock-solid mount, and a set of three eyepieces that you can use to change magnification.

What is the best time to see the moon?

The best time to explore the moon’s surface with a telescope or binoculars is when its disk is half lit (called the quarter moon), or when it’s a crescent. Pay particular attention to the boundary line between the sunlit side and the dark part of the disk. It’s along this region that you’ll see jaw-dropping views of long shadows cast by jagged mountain ranges and uplifted crater rims. Encourage children to imagine what it was like for Apollo 13 astronauts as they looked out their spacecraft at the moon below, as they orbited it more than 50 years ago.

What is the North Star?

That’s Polaris (aka the North Star), part of the Ursa Minor (“little bear”) constellation. For those in the Southern Hemisphere, the distinctive and highly visible Southern Cross is a great jumping-off point to star hop around the night sky.