Tom Greve - Astronomers

EYES TO THE SKIES

As long as people have been on Earth, they have stared with wild wonder into the night sky. What is out there? Why are the stars twinkling? How far away is the Moon?

Human understanding of the Moon, stars, and worlds beyond our own has grown by leaps and bounds over just the past few generations.

Stars are so far from Earth that their light is distorted by Earths atmosphere and they sometimes appear to twinkle. Visible planets, such as Venus, do not twinkle because they are much closer.

FIELD NOTES

Most astronomers concentrate on a particular question or area of astronomy: planetary science, solar astronomy, the origin or evolution of stars, or the formation of galaxies. Observational astronomers spend their time designing and carrying out observational programs with a telescope to answer a question or test the predictions of theories.

The universe beyond our planet is limitless. So are the mysteries hiding within its cold, dark void.

Over centuries, scientific minds have used their own observation, and, more recently, stunning advances in technology, to pull back the curtain on just a tiny fraction of the endless unknowns of outer space.

Giant telescopes housed in observatories act as a kind of window to the stars. Many observatories are built in remote locations at high altitudes.

Observatory on Mauna Kea, Hawaii

Earth is one of eight planets in our solar system. Astronomers call the four nearest the Sun the rocky planets. The four farthest from the Sun are called the gas giants.

realms beyond our own solar system are astronomers. They play an important role in understanding our Earth, and its place in a universe so vast, it can sometimes defy our understanding.

Astronomy is a science. While life sciences such as biology are more concerned with the study of living things, astronomers study the physical makeup and activity of objects in space.

WATCHING GRAVITY, KEEPING TIME

The scientific knowledge we have about our planet Earth, its Moon, other planets in our solar system, asteroids, the Milky Way galaxy, and the infinite number of galaxies beyond it, is based on the work of astronomers.

Thanks to gravity, our Sun, which is really a medium-sized star, holds eight planets and other objects in orbit. But there are countless other suns and solar systems in our galaxy, and there are countless other galaxies beyond our own. This infinite expanse makes up the universe, or the cosmos.

Astronomers believe there are billions of solar systems beyond our own. That means Earth is like a grain of sand on an entire beach of planets, moons, and stars.

If a person could stand on a planet in another galaxy and identify Earths solar system in the sky, it would appear as nothing more than a tiny speck of light, just like the tens of thousands of specks of light we can see from Earth on a clear night.

FIELD NOTES

The time astronomers spend at a telescope collecting data for analysis is only the beginning. Most of their time is spent in an office analyzing data, creating computer programs that allow them to more efficiently search through the data, writing research papers, and attending meetings.

Astronomy research shows that the order of the objects in outer space, our planet orbiting around our Sun, and countless other planets orbiting around countless other suns, are all a result of the forces of gravity, and time.

Same force, different scale: no matter how hard somebody throws or kicks a ball, the force of gravity will always cause it to land on the ground. Gravity also keeps the Sun, stars, moons, and planets in their places.