The galaxy is extremely large. It is elliptical in shape, and measures roughly 80,000 light years on its short axis and 200,000 light years on its long axis. Even a single light year (the distance light travels in a year) is a very long distance, approximately seven trillion miles. The only way we have of investigating the galaxy at large is by telescope, and even the best telescopes can only see so much. When you are looking at something that is on the order of quadrillions of miles away, it is really hard to see. That is why it is difficult to find Earth-like planets elsewhere in the galaxy.
It is difficult to find Earth-like planets elsewhere in the galaxy because they are small and dim compared to their host stars, making them hard to detect using current observational techniques. Additionally, Earth-like planets need to be at the right distance from their star (in the habitable zone) to support liquid water and potentially life, which further limits the number of potential candidates.
It is estimated that there are billions of stars in the Milky Way galaxy that could potentially have Earth-like planets within their habitable zones. The exact number is difficult to determine with certainty due to the vastness of our galaxy and the limitations of current technology.
The closest galaxy that has planets is the Andromeda galaxy. It is the nearest galactic neighbor to the earth. The Milky Way has other planets too.
Planets orbit stars, stars orbit a galaxy. Planets are not "on" anything. A lot of stars out there have planets - we are just finding out how many now that we have better techniques to find them. So probably all galaxies have at least some stars with planets.
In our own solar system, the planet whose density and internal structure most resemble that of the Earth is Venus. There may be other planets elsewhere in the galaxy which resemble Earth even more closely, but we have not had the opportunity to observe them.
The Sun, all its planets and the galaxy in which the Sun sits all rotate.
Earth
earth
It is estimated that there are billions of stars in the Milky Way galaxy that could potentially have Earth-like planets within their habitable zones. The exact number is difficult to determine with certainty due to the vastness of our galaxy and the limitations of current technology.
Compared to some other planets in the same galaxy, yes; it is actually fractions of the size of other planets in this galaxy
The closest galaxy that has planets is the Andromeda galaxy. It is the nearest galactic neighbor to the earth. The Milky Way has other planets too.
IR as in infrared? Who says it is "critical"? Search for life elsewhere in the Galaxy, or here on Earth?
Mars and Earth are planets in a galaxy called the Milky Way, inside the universe.
well earth
Planets orbit stars, stars orbit a galaxy. Planets are not "on" anything. A lot of stars out there have planets - we are just finding out how many now that we have better techniques to find them. So probably all galaxies have at least some stars with planets.
Yes, the Andromeda Galaxy has planets. While they have not been directly observed due to the vast distance from Earth, scientists believe that planets exist around many stars in the Andromeda Galaxy, much like in our own Milky Way Galaxy.
No. Earth is the 5th largest of the eight planets in the solar system. There are many more planets in the galaxy in other solar systems with numbers estimated in the hundreds of billions. Many that we know of are larger than Earth while some are smaller.
...only as a metaphor. The Earth is a planet that is in the Milky Way galaxy. The Earth is not a galaxy. No, the Earth is a planet which orbits the Sun (which is a star) along with several other plants, this is called the solar system. Our Sun and its planets along with millions of other stars form a galaxy called The Milky Way.