4.6 Astronomical Data & Collection Methods

Introduction

When you look at the night sky, you might see what appears to be a black curtain with millions of tiny holes in it. Many early people thought all of the stars were the same distance from Earth, fixed on a single layer in space. When instruments were developed to see farther into space, people began to realize that their perceptions were not correct.

As technology advances, we can see further and further into space. Determining the positions of bodies in space and their distances from each other allows us to develop a fuller understanding of the universe.

Today, a mix of ancient principles and new technologies are employed to see space in the most accurate way possible.

This section explores the many technologies developed for space exploration. 

Observing From Earth

Telescopes allow us to view space from the comfort of our own backyard. The first telescope was an optical telescope. Optical telescopes collect and focus visible light so that you can see a magnified image of a distant object. Optical telescopes come in a variety of sizes; from small, portable ones you could use in your backyard, to huge stationary ones in scientific observatories.

Optical telescopes are not the only kind of telescopes available. Visible light makes up only a small portion of the radiation energy in the universe. The electromagnetic spectrum shows these different forms of energy.

Other types of telescopes use these other forms of energy to create pictures of the universe.

Observing from Space

Our view of space from Earth is not perfect. Air and light pollution, cloudy weather, and distortion from heat and atmosphere are all factors that can obscure the view of space. To get a better view, astronomers position instruments outside the Earth's atmosphere.

Some devices that astronomers use in space are satellites and probes.

A satellite is anything that orbits around something else. There are natural satellites such as our Moon, and artificial satellites such as communications devices orbiting Earth right at this moment.

Probes are devices sent, with no human pilot, to another celestial body to gather information. Sending probes into space is usually less costly than sending humans, and less dangerous. However, there is some debate as to whether a machine can gather information as well as a human being. What do you think?

Over fifty years ago the Soviet Union launched the first artificial satellite to orbit the Earth. Since then, countries all over the world have launched satellites into space. Today there are over 9000 artificial satellites orbiting Earth, but only about one-third of these are actually functioning. That means there are over 6000 pieces of space junk orbiting the Earth.

The Hubble Space Telescope

Hubble, the observatory, is the first major optical telescope to be placed in space, the ultimate mountaintop. Above the distortion of the atmosphere, far far above rain clouds and light pollution, Hubble has an unobstructed view of the universe. Scientists have used Hubble to observe the most distant stars and galaxies as well as the planets in our solar system. Hubble's launch and deployment aboard the space shuttle Discovery, in April 1990, marked the most significant advance in astronomy since Galileo's telescope. Thanks to four servicing missions and more than 25 years of operation, our view of the universe and our place within it has never been the same.

Hubble is one of the most productive scientific instruments ever built. Hubble does not travel to stars, planets or galaxies. It takes pictures of them as it whirls around Earth at about 17,000 mph. Hubble has traveled more than 4 billion miles along a circular low Earth orbit currently about 340 miles in altitude. Hubble has peered back into the very distant past, to locations more than 13.4 billion light years from Earth. Hubble weighed about 24,000 pounds at launch and currently weighs about 27,000 pounds following the final servicing mission in 2009 – on the order of two full-grown African elephants. Hubble's primary mirror is 2.4 meters (7 feet, 10.5 inches) across. Hubble is 13.3 meters (43.5 feet) long -- the length of a large school bus.

Spaceplanes

A spaceplane is an aerospace vehicle that operates as an aircraft in Earth's atmosphere, as well as a spacecraft when it is in space. It combines features of an aircraft and a spacecraft, which can be thought of as an aircraft that can endure and maneuver in the vacuum of space or likewise a spacecraft that can fly like an airplane. Typically, it takes the form of a spacecraft equipped with wings, although lifting bodies have been designed and tested as well. The propulsion to reach space may be purely rocket based or may use the assistance of airbreathing jet engines. The spaceflight is then followed by an unpowered glide return to landing.

The International Space Station

The International Space Station (ISS) is the most complex international scientific and engineering project in history and the largest structure humans have ever put into space. This high-flying satellite is a laboratory for new technologies and an observation platform for astronomical, environmental and geological research. As a permanently occupied outpost in outer space, it serves as a stepping-stone for further space exploration. The space station flies at an average altitude of  400 kilometers above Earth. It circles the globe every 90 minutes at a speed of about 28,000 kph. In one day, the station travels about the distance it would take to go from Earth to the moon and back. The space station can rival the brilliant planet Venus in brightness and appears as a bright moving light across the night sky. It can be seen from Earth without the use of a telescope by night sky observers who know when and where to look.

Five different space agencies representing 15 countries built the $100-billion International Space Station and continue to operate it today. NASA, Russia's Roscosmos State Corporation for Space Activities (Roscosmos), the European Space Agency, the Canadian Space Agency and the Japan Aerospace Exploration Agency are the primary space agency partners on the project. 

Watch live video from the Space Station below!

Click here to learn more about the International Space Station.

Cassini Spacecraft & Exploration of Saturn

NASA's Cassini spacecraft is back in contact with Earth after its successful first-ever dive through the narrow gap between the planet Saturn and its rings on April 26, 2017. The spacecraft is in the process of beaming back science and engineering data collected during its passage, via NASA's Deep Space Network Goldstone Complex in California's Mojave Desert.

After almost 20 years in space, NASA's Cassini spacecraft begins the final chapter of its remarkable story of exploration: its Grand Finale. Following a final close flyby of Saturn's moon Titan, Cassini has leapt over the planet's icy rings and began a series of 22 weekly dives between the planet and the rings.

End of Mission: 15 Sep 2017 No other mission has ever explored this unique region. What we learn from these final orbits will help to improve our understanding of how giant planets – and planetary systems everywhere – form and evolve.

Curiosity Rover & Exploration of Mars

Curiosity is a car-sized robotic rover exploring Gale Crater on Mars as part of NASA's Mars Science Laboratory mission. Curiosity was launched from Cape Canaveral on November 26, 2011, aboard the MSL spacecraft and landed on Aeolis Palus in Gale Crater on Mars on August 6, 2012. The Bradbury Landing site was less than 2.4 km  from the center of the rover's touchdown target after a 560 million km  journey. The rover's goals include: investigation of the Martian climate and geology; assessment of whether the selected field site inside Gale Crater has ever offered environmental conditions favorable for microbial life, including investigation of the role of water; and planetary habitability studies in preparation for future human exploration.

Parker Solar Probe

NASA’s Parker Solar Probe will be the first-ever mission to "touch" the sun. The spacecraft, about the size of a small car, will travel directly into the sun's atmosphere about 4 million miles from our star's surface. It was named after Eugene Parker who discovered 'solar wind'. The launch of this unprecedented mission is scheduled for 2018.