Are there galaxies in the milky way

If you can estimate the rate at which stars have formed, you will be able to estimate how many stars there are in the Universe today. In , an image from the Hubble Space Telescope HST suggested that star formation had reached a peak at roughly seven thousand million years ago. Recently, however, astronomers have thought again. The Hubble Deep Field image was taken at optical wavelengths and there is now some evidence that a lot of early star formation was hidden by thick dust clouds.

Dust clouds block the stars from view and convert their light into infrared radiation, making them invisible to the HST. But Herschel could peer into this previously hidden Universe at infrared wavelengths, revealing many more stars then ever seen before.

Soon Gaia will launch, which will study one thousand million stars in our Milky Way. It will build on the legacy of the Hipparchus mission, which pinpointed the positions of more than one hundred thousand stars to high precision, and more than one million stars to lesser precision. They interact and even collide. However, gravitational interactions between colliding galaxies could create new waves of star formation, supernovas and even black holes.

Four billion years from now, our own Milky Way galaxy is destined for a collision with the neighboring spiral Andromeda galaxy. The Sun will likely be flung into a new region of our galaxy, but our Earth and solar system are in no danger of being destroyed.

Andromeda, also known as M31, is now 2. Computer simulations derived from Hubble data show that it will take an additional two billion years or more after the encounter for the interacting galaxies to completely merge under the tug of gravity. They will reshape into a single elliptical galaxy similar to the kind commonly seen in the local universe.

Simulations show that our solar system will probably be tossed much farther from the galactic core than it is today. There is a small chance that M33 will hit the Milky Way first. The appearance and make-up of galaxies are shaped over billions of years by interactions with groups of stars and other galaxies. While we don't know for certain how galaxies formed and took the many shapes that we presently see, we have some ideas about their origins and evolution.

Using supercomputers, scientists can look back in time and simulate how a galaxy may have formed in the early universe and grown into what we see today. Scientists estimate the age of the universe at Because the deeper you look into space, the further you see back in time, we can conclude that galaxies several billions of light-years away formed fairly soon after the big bang.

While most galaxies formed early, data indicates that some galaxies have formed within the past few billion years — relatively recently in cosmic terms.

The early universe was filled mainly with hydrogen and helium, with some areas slightly denser than others. Gravity caused the gas in these clouds to collapse and form the first generation of stars. These first stars rapidly burned out. Gravity continued to collapse the clouds. As other clouds came close to each other, gravity sent them careening into one another and knitted the clouds into larger, spinning packs.

As the clouds further collapsed, they became rotating disks, which amassed more gas and dust. New stars formed, creating extensive spiral arms filled with colonies of stars. Sprinkled along the periphery were globular clusters, along with a halo of gas, dust and dark matter.

While Hubble is unable to see the very first galaxies, it can track the development of galaxies over much of cosmic time. The series of Hubble Deep Field images and other deep surveys have uncovered galaxies at many different distances out in the universe, and therefore at many different times in their development.

IC has a low surface brightness and lies in Camelopardalis, near the plane of the Milky Way in our sky. Credit: Tony Hallas. Newsletter Sign up for our email newsletter for the latest science news. Sign Up. He was initially excited, believing he had recorded a nova, an exploding star.

He marked the star, which lies between two tick marks he drew at the top right on the plate, with the letter N. The star turned out to be a Cepheid variable, and Hubble used it to prove that the distance to the Andromeda Galaxy was far greater than astronomers thought. NGC in Coma Berenices is the brightest and most prominent galaxy in our sky that is oriented perfectly edge-on to our line of sight.

We see its disk as a thin, silvery needle. Some 57 million light-years off, it lies in the Virgo Cluster and has a prominent central bulge, suggesting it may be a barred spiral. Credit: Adam Block. Perseus A, also called NGC , is an eruptive galaxy at the core of the Perseus Cluster, which is made up of some 1, galaxies about million light-years away.

The dominant member of the Perseus Cluster, Perseus A is a Seyfert galaxy with an active nucleus, powered by a million-solar-mass black hole in its core. The weirdly distorted elliptical galaxy NGC in Pisces lies at a distance of million light-years. The neighboring spiral galaxy NGC lies just above it. Multiple shells and tidal tails surround NGC , caused by interactions with its neighbors and by density waves that propagate through the medium.

This mammoth object stretches , light-years across — two and a half times the diameter of the Milky Way. Credit: P-A. One of the greatest edge-on galaxies in the sky, and the one most people say looks like a flying saucer, is the Sombrero Galaxy M in Virgo.

It consists of a great rotating disk with a prominent dust lane edging it, consumed by a glowing halo of gas and stars. It lies 43 million light-years away and is about half the size of the Milky Way, sporting a diameter of 49, light-years. Elliptical galaxies like M49 in Virgo are huge spheres of stars that float in an ellipsoidal cloud. Although their diameters are often similar to large spiral galaxies, they can hold vastly more mass because they are shaped like a football rather than a disk.

This galaxy lies some 56 million light-years away and is one of the more massive galaxies in the Virgo Cluster. Already a subscriber? Want more? More From Discover. Recommendations From Our Store. Stay Curious. View our privacy policy. Website Accessibility. Only three galaxies outside our own Milky Way Galaxy can be seen without a telescope, and appear as fuzzy patches in the sky with the naked eye.

The closest galaxies that we can see without a telescope are the Large and Small Magellanic Clouds. These satellite galaxies of the Milky Way can be seen from the southern hemisphere.

Even they are about , light years from us. The Andromeda Galaxy is a larger galaxy that can be seen from the northern hemisphere with good eyesight and a very dark sky.

It is about 2. The other galaxies are even further away from us and can only be seen through telescopes. An all-sky image shows the flat plane of the Milky Way galaxy. Credit: E. Since we can't get outside the Milky Way, we have to rely on markers of spiral arms like young, massive stars and ionized clouds.