Exoplanets, The Frontier of Modern Astronomy

By DENZEL CARTER JACKSON

Exoplanets have been found in a relatively small region of our galaxy, the Milky Way. According to NASA's Kepler Space Telescope, there are more planets in the universe than stars.

Our solar system's exoplanets comprise similar elements to our planets, but their mixtures may differ. By measuring the sizes (diameters) and masses (weights) of exoplanets, we can determine their compositions, which range from very rocky (like Earth and Venus) to very gaseous (like Jupiter and Saturn). Some planets may be dominated by water, ice, or iron, while others are dominated by iron or carbon. A stellar world with lava seas, a puffy planet, and a planet whose core is as dense as Styrofoam have been identified.

Since then, we've discovered thousands of exoplanets using various detection methods. From Earth, it is infrequent to see an exoplanet through a telescope the way you might see Saturn. Direct imaging has only been used to find a handful of exoplanets (and these are usually young gas giants orbiting very far from their stars).

Exoplanets are now part of our universe. There are thousands of confirmed planets. This is only a tiny part of the entire galaxy. As we increase the number and observing power of robotic telescopes deployed in space, the number could rise into the tens of thousands within a decade.

Since then, we've discovered thousands of exoplanets using various detection methods. From Earth, it is infrequent to see an exoplanet through a telescope the way you might see Saturn. That's called direct imaging, and only a handful of exoplanets have been found this way (and these are young gas giant planets orbiting very far from their stars).

Exoplanets are now part of our universe. Thousands of planets have been confirmed. This is only a tiny sampling of the galaxy. By deploying more robotic telescopes into space, we will see tens of thousands of stars within a decade.

• Language: English
• Publisher: DTTV PUBLICATIONS
• Release date: May 16, 2022
• ISBN: 9798201343125

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DENZEL CARTER JACKSON

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Introduction

Exoplanets have been found in a relatively small region of our galaxy, the Milky Way. According to NASA's Kepler Space Telescope, there are more planets in the universe than stars.

Our solar system's exoplanets comprise similar elements to our planets, but their mixtures may differ. By measuring the sizes (diameters) and masses (weights) of exoplanets, we can determine their compositions, which range from very rocky (like Earth and Venus) to very gaseous (like Jupiter and Saturn). Some planets may be dominated by water, ice, or iron, while others are dominated by iron or carbon. A stellar world with lava seas, a puffy planet, and a planet whose core is as dense as Styrofoam have been identified.

Since then, we've discovered thousands of exoplanets using various detection methods. From Earth, it is infrequent to see an exoplanet through a telescope the way you might see Saturn. Direct imaging has only been used to find a handful of exoplanets (and these are usually young gas giants orbiting very far from their stars).

Exoplanets are now part of our universe. There are thousands of confirmed planets. This is only a tiny part of the entire galaxy. As we increase the number and observing power of robotic telescopes deployed in space, the number could rise into the tens of thousands within a decade.

Since then, we've discovered thousands of exoplanets using various detection methods. From Earth, it is infrequent to see an exoplanet through a telescope the way you might see Saturn. That's called direct imaging, and only a handful of exoplanets have been found this way (and these are young gas giant planets orbiting very far from their stars).

Exoplanets are now part of our universe. Thousands of planets have been confirmed. This is only a tiny sampling of the galaxy. By deploying more robotic telescopes into space, we will see tens of thousands of stars within a decade.

Thousands of worlds have been discovered using space telescopes by observing transits, the slight dimming of light from a star when its tiny planet passes in front of our telescopes. A majority of exoplanets are found indirectly: by measuring the dimming of a star as a world passes in front of it, which is called the transit method, or by watching the spectrum of a star for subtle Doppler shifts caused by a planet. Gravitational lensing, or the so-called wobble method, is another detection method.

However, when multiple methods are employed, we can learn the vital statistics of entire planetary systems without directly imaging the planets. TRAPPIST-1, about 40 light-years away, has seven roughly Earth-sized planets orbiting a small, red star.

Ground and space telescopes have been used to study the TRAPPIST-1 planets. Researchers determined the diameters of these seven closely spaced planets and their subtle gravitational influence on each other. They also decided on each planet's mass.

The seven planets of this system are the most well-known outside of our own, though much remains unknown about them, such as whether they have atmospheres, oceans, or ice sheets. Now that we know their mass and diameter, we can build a model for them. Furthermore, scientists can estimate the temperature of these planets from the amount of energy radiated by their stars. Even if you were standing on one, we could make reasonable estimates of the light level and the color of the sky.

THE TRAPPIST EXOPLANET SYSTEM

Part One - Looking at Exoplanets

Most exoplanets have been discovered in our galaxy, the Milky Way. According to NASA's Kepler Space Telescope, there are more planets in the universe than stars.

As we measure exoplanets' sizes (diameters) and masses (masses), we can tell how rocky they are (like Earth and Venus) and how gas-rich they are (like Jupiter and Saturn). Exoplanets are elements similar to those on our solar system's planets, but their mixes may differ. Water or ice may dominate some planets, while iron or carbon may dominate others. There are Earth-sized lava worlds encased in molten seas, puffy planets, dense cores of planets still orbiting their stars, and worlds with molten seas.

Exoplanets are rare for astronomers to see through their telescopes, much like you might see Saturn through a telescope from Earth. Direct imaging is used to find exoplanets (typically young gas giants orbiting very far from their stars). Thousands of exoplanets have been seen since the 1990s, and we've detected them with various methods since then.

Exoplanets are now part of our universe. There are thousands of confirmed planets. This is only a tiny part of the entire galaxy. As we increase the number and observing power of robotic telescopes deployed in space, the number could rise into the tens of thousands within a decade.

Thousands of worlds have been discovered using space telescopes by observing transits, the slight dimming of light from a star when its tiny planet passes in front of our telescopes. There are two fundamental techniques for finding exoplanets: measuring the dimming of a star passing in front of a world, called the transit method, or monitoring the spectrum of a star