Our understanding of planets beyond our own solar system is still in its infancy. Because planets in other solar systems are extraordinarily difficult to see directly, astronomers have had to come up with innovative ways to hunt for them. Only recently have our technology and techniques been up to the task of finding exoplanets.
The quest took a huge leap forward in 2000 when Hubble studied the exoplanet HD 209458 b, the first extrasolar planet known to make "transits" across the face of its star. Hubble became the first telescope to directly detect an exoplanet's atmosphere and survey its makeup. As a planet passes between its star and us, a small amount of light from the star is absorbed by the gas in the planet's atmosphere, leaving chemical "fingerprints" in the star's light. In the case of HD 209458 b, Hubble detected the signature of sodium that did not belong to the star. It was the mark of sodium gas in the atmosphere of the planet.
Every bubble is a universe Since then, astronomers have discovered many more planets transiting their stars, and have used Hubble to investigate some of those planets' atmospheres. In the atmosphere exoplanet HD 189733 b, located 63 light-years away, Hubble detected methane. This was the first organic molecule identified in the atmosphere of a planet outside our solar system.
In 2018, astronomers Hubble conducted the first spectroscopic survey of several Earth- sized planets orbiting in their star's habitable zone, a region at a distance from the star where liquid water, the key to life as we know it, could exist on the planets' surfaces. Only 40 light-years away - a stone's throw on the scale of our galaxy scientists found seven planets orbiting the red dwarf star TRAPPIST-1. Four of these planets lie in the star's habitable zone.
Question 1: Why is it challenging for astronomers to directly observe planets in other solar systems, and how have they addressed this challenge?
Answer: It is challenging for astronomers to directly observe planets in other solar systems because they are extraordinarily difficult to see. Astronomers have addressed this challenge by developing innovative techniques and technology to hunt for exoplanets.
Question 2: How did Hubble contribute to the study of exoplanets in 2000, and what significant discovery was made regarding the exoplanet HD 209458 b?
Answer: In 2000, Hubble studied the exoplanet HD 209458 b, becoming the first telescope to directly detect an exoplanet's atmosphere and survey its makeup. The significant discovery made regarding HD 209458 b was the detection of sodium gas in the planet's atmosphere, identified through the absorption of light from its host star.
Question 3: What is the significance of detecting methane in the atmosphere of the exoplanet HD 189733 b, and how was this discovery made?
Answer: The significance of detecting methane in the atmosphere of HD 189733 b is that it was the first organic molecule identified in the atmosphere of a planet outside our solar system. This discovery was made using Hubble's observations of the planet's atmosphere.
Question 4: What was the purpose of the spectroscopic survey conducted by astronomers using Hubble in 2018, and what did they discover about the TRAPPIST-1 system?
Answer: The purpose of the spectroscopic survey conducted by astronomers using Hubble in 2018 was to study several Earth-sized planets orbiting in their star's habitable zone. They discovered that the TRAPPIST-1 system, located only 40 light-years away, contains seven planets, four of which lie in the star's habitable zone.
Question 5: How does the transit method help astronomers detect exoplanets, and what information can be gleaned from this method?
Answer: The transit method involves observing a planet as it passes between its star and the observer. By measuring the slight decrease in the star's brightness during the transit, astronomers can infer the presence of an exoplanet. This method provides information about the planet's size, orbital period, and sometimes its atmosphere.
Question 6: What does the passage suggest about the potential for finding habitable exoplanets, and what implications does this have for the search for extraterrestrial life?
Answer: The passage suggests that the discovery of planets in their star's habitable zones, where liquid water could exist on the surface, increases the potential for finding habitable exoplanets. This has significant implications for the search for extraterrestrial life, as it expands the range of environments where life could potentially exist beyond Earth.
