Category Archives: SPACE FACTS

What is a neutron star?

Neutron Star Definition

Neutron star definition.

A neutron star is an incredibly compact star, which is only 10-30 km. in diameter, but weighs 1.4 – 2.3 times as much as the Sun. A neutron star can be formed after a heavy star dies in a supernova explosion. When a heavy star has burned all its hydrogen into helium, using fusion, the temperature rises in its core until it is warm enough for burning helium. When the helium is burned, the temperature rises further and the process continues until nickel 62 is formed. Nickel has the highest binding energy per nucleus at the core. Thus, the star can not form more energy by merging or fissioning nickel, and therefore there is no energy to withstand gravity pressure. This causes the star to collapse under its own weight in a very short time.

Therefore, the electrons (which are negative) are pushed into the positive atomic nuclei. This means that the star consists mainly of neutral core particles – neutrons. The substance surrounding the nucleus encounters an impermeable wall, and therefore an outward pressure wave causes the material to flow into space, in a giant explosion called a supernova. Once all the gas is blown away, only the neutron star is left and only a teaspoon of the interior would weigh 100 million tons here on earth. The finished neutron star can not be pressed more together.

When a star becomes a size that is too big to support itself, it breaks down because of its own enormous gravity. When this happens, the star is broken in what is called a supernova. Sometimes, out of the ashes of such a devastating event comes another type of star, a so-called neutron star, consisting mainly of neutrons, which are electrons and photons together. Neutron stars are extremely hot and have a high pressure from gravity.

Neutron stars are supposed to be the remainings of a normal star which concluded its life as a supernova. In a supernova explosion, a star first blows its outer layer, creating a very compact star called  white dwarf. At one point, the white dwarf passes a critical border for its size and collapses. At the collapse, the substance is squeezed so much that its electrons are absorbed in the protons of the atomic nuclei, and neutrons are formed. A neutron star can therefore also be perceived as one giant nuclear nucleus consisting exclusively of neutrons. Neutron stars are so small that it is almost impossible to ebserve them. But they are often detected by the radiation they emit. The emission of radiation is related to the star’s rotation, which can be at several hundred rpm.

History of Neutron Stars

Neutron stars have been known since the beginning of the galaxy, but they were discovered and began to be investigated in 1933 when Walter Baade and Fritz Zwicky emerged with the idea of ​​a neutron star existence. It was a year after the neutron particle was discovered. The first neutron star was found in Crab Street in 1965 by Antony Hewish. The study of neutron stars continued and more was discovered through the 1970s and lasted till today. Studying these stars also helped the discovery of pulsaries.

Size

Neutron stars are relatively small, but they have a large mass. Typical neutron stars have a radius at a location between 10 and 20 km, which corresponds to a diameter of about 12 miles. Our sun, in contrast, is about 50,000 times as high as the average neutron star. Although the neutron star is smaller, its particles are very dense and that gives it a lot that is 1.5 times larger than the Sun. The crust of a neutron star is very thin compared to the rest of the star, only one mile thick, consisting mainly of neutrons, with a touch of other particles.

A star’s destiny depends on its mass. The heavier a star is, the shorter the time it lives (it is said that a star “lives” as long as nuclear core fusion processes occur in its interior parts).

For example, the sun is a typical average star with a mass of about 2 * 10 30  kg (M sol ) and it is expected to have a life span of about 10 billion. year. As the solar system already has an age of just 4.5 billion years, the Sun is now about halfway through its cycle. There are stars with a mass in the range of barely 0.1 M solar and up to over 100 M of sun .

In the vast majority of a star’s life, energy is released by the fusion of hydrogen. It is precisely the radiation pressure of this released energy that prevents the star from collapsing under the influence of its own weight. In the final phase of its lifetime (the last 10%), the star breathes and becomes a giant star, while the inner parts of the star are pulling together.

The star’s radius typically becomes several hundred times larger in this final stage. In the case of the Sun, it will grow from its current radius of approx. 700 000 km and all the way to Earth’s lane (150 million km). In this final phase of its life cycle, the star can survive through the fusion of a sequence of heavier elements (helium → carbon → oxygen → neon → magnesium → sulfur → silicon → iron). How far a star’s inner parts could be reached in this process depends on the mass of the star.

When energy can no longer be released by merger, the outbound radiation pressure stops and the star collapses and becomes a so-called compact object. Stars that have a mass less than 8 M sun end their days like a white dwarf. The outer parts of the original star are thrown into a beautiful planetary fog (which has nothing to do with the formation of planets, as you thought in ancient times). If the original star has a mass of more than 8M of sun , it will explode into a supernova explosion and leave a neutron star (In the most extreme case where the star initially weighs more than 25M of sun it will collapse into a black hole).

A typical neutron star

A typical neutron star has a radius of only 10 km and a mass of 1.5 M solar . A cubic centimeter material from a neutron star has a mass of hundreds of millions of tons. In other words, it is extremely compact and can be considered as one major nuclear nucleus. As the name suggests, a neutron star consists mainly of neutrons, but also a smaller proportion of protons.

When the neutron stars are so small, they are very hard to spot with an optical telescope. Fortunately, however, some neutron stars have a very powerful magnetic field and a fast rotation that emit radio waves in a cone-shaped beam – exactly like a lighthouse that glows over the dark ocean at night. These neutron stars are called radio pulses and can be observed with large radio telescopes.

Another type of neutron stars we can detect here from Earth is neutron stars in so-called binary systems – ie. neutron stars circle around another star. If the two stars are close enough to each other, the neutron star can, in other words, eat the gas from the other star, thereby emitting a powerful X-ray. These neutron stars can thus be seen with X-ray detectors aboard satellites in circulation around the Earth.

The first neutron star was discovered in 1967 and today we know more than 2000 neutron stars in Mælkevejen. The hitherto closest known of these are at a distance of approx. 280 light years

Interesting Facs About Moon

The Moon Surface

The sight of the full Moon is something to behold. Depending where you are on earth when you look at the full moon there appears to be a face on it. There are two roundish soft gray eyes that look slightly downward, Between the eyes there is a nose that looks like an elongated circle. The mouth of the face is roundish and doesn’t have a very inviting expression, but the longer you look at it, the more it looks like a friendly smile. If you look long enough, you can swear that the face in the moon is winking at you!


The origin of the Moon

Scientists agree that the moon is 4.527 billion years old and originated from the earth.It was formed when a large celestial body, the planet Theja, collided with the earth.. The collision
was so violent that the heat generated from it fused the two planets together and at th esame time ejected an enormous molten mass into space. This molten mass cooled and formed the moon that now revolves around earth.

The lunar surface

The above theory of how the moon was created has been confirmed by the many trips to the moon.. Rocks from the moon, called moonstones, have been examined and found to be made up of the same materials that make up the earth’s crust.

Impact craters

The lunar surface is, for the most part, covered with impact craters (moon craters). The craters were most likely caused by meteorites.A moon crater looks like a round bowl with a high ring around it. This is called a ring mountain. Large craters with low rings and shallow bowls are called shore or ring plains. The craters range from very ancient craters to fairly new craters and range in size from a few meters to many kilometers wide. Just on the visible side of the moon alone, there are an estimated 300,000 craters with a diameter of more than one kilometer. The number of smaller craters are much greater. The largest craters have a diameter of more than two hundred kilometers. The Atkins Basin has a size of 2000 kilometers wide and 13 kilometers deep, the largest and deepest. The oldest craters on the moon are believed to be over two billion years old.
Craters that are lined up one in front of the other are called chain craters. Sometimes these chain craters are connected by shivering. (What is Shivering?)

A rille on the Moon is a meandering streams of dozens, sometimes hundreds of kilometers long with a width of a few kilometers.A suspicion that this caused by erosive action of lava exist. The grooves usually found in a mare (plural Maria) but sometimes they are found also in the many craters on the Moon. ( I have no idea what this section is trying to say. What is a rile? The title of this section is Shiver, but there is nothing mentioned about it.)

A mare or Maan Zee are the dark spots that we can observe from Earth. About 16% of the lunar surface consists of Maria (mare is Latin for sea). The Maria is actually large volcanic plain, composed of basalt. Basalt is a rock formed by the solidification of lava. The Maria occur mainly on the side of the moon that we can observe on Earth, the ‘front’ of the moon. The explanation for this is that the ‘front’ of the Moon is located below the ‘back’ of the moon. The ‘back’ of the moon possesses once again a larger number of craters.
The name mare (Maan zeeee) is given to these dark spots because scientists believe that, at one time, they were real seas or oceans.

Water on the Moon

It has always been assumed tha the moon never had any water.. NASA, however, on 13 November 2009 announced that a satellite discovered water on the moon. When the satellite performed it’s planned crash on the moon, it raised a dust cloud which included ice crystals. This data from the satellite was transmitted to Earth and analyzed. From this alalysis, The NASA Lunar Science Institute was able to confirm that three types of water are present on the moon. They are:
water from comets, water that occurs on the lunar farside. Researchers found it in rocks collected during the Apollo missions, Until that time, researchers thought that water could not have existed on the moon. Magmatic water gives clues about the volcanic processes of the moon and how magmatic processes changed when the moon cooled.
water coming from the sun. This water would arise from actions by the solar wind which is The constant flow of charged particles (ions) that constantly bombards the moon, could have deposited water on the moon

A new study in April 2014 suggests that the amount of water on the moon is overestimated.

This was becasue of a mineral that is found on the moon in abundance, Apatite, Apatite contains a key element needed for water, Hydrogen. Becasue it is found in great amounts, it was believed that there had to be more water on the moon than what was thought. It was discovered that the hydrogen found in Apatite is not a good indicator of the amount of water that is actually found on the moon.

Volcanoes on the Moon

Are there volcanoes on the moon?  since the mare (the maanzee) consists of volcanic plains, there has to be!. Currently, there are no active volcanoes on the moon The last volcanic eruption on the surface of the moon took more than a billion years ago. The iron core of the moon (as with the ground) is still be able to turned to a liquid according to researchers. This Research was led by Wim van Westrenen, Mirjam van Kan Parker, Nichiketa Rai and Elodie Tronche of the Faculty of the earth at the Free University of Amsterdam. the research also found that the magma of the moon was so heavy, it acted like an inverted volcano. The magma seeped through the surrounding bedrock down to the core, much different to what we are familiar with here on earth,

Mountains on the Moon

The mountains on the moon are the oldest part of the surface. The mountains were created by impacts of meteorites and asteroids (ring mountains). Hot lava flowed over the lower parts of the lunar surface and filled the lunar seas (maria). As the moon cooled, volcanic activity came to an end about three billion years ago. Many mountains on the moon are named after mountain ranges on earth:

–  The Apennines. On the moon, the Apennines are one thousand kilometers long.
–  Carpathian mountains up to 2,300 meters
–  The Caucasus Jura to 6500 meters.

Fine Sand on the Moon

A thick layer of fine sand coveres the lunar surface.which is called regolith. The depth of hte regolith can vary from very shallow spots, only 10 centimeters in depth, to very deep spots measuring many meters indepth.  This sandy layer is The result of numerous micro meteorites that have, over the years, turned the lunar surface into a large dusty ‘sandbox’. The absence of any earthly elements ensure that any mark on the moons surface is well preserved. For example the footsteps of Neil Armstrong, who is the first man set foot on the Moon in 1969, have remained unchanged for all this time

The face of the moon

With a little imagination and depending where you are on earth, you can see a face on the moon when it is full. From the Netherlands and Belgium you are able to see two eyes. The right eye (the dark spot) is called the sea of brightness and has a diameter of about seven hundred kilometers. The left eye is called the sea of rain. The diameter of this “eye” is even greater. As many as a thousand kilometers in diameter. Between the two eyes we find something that resembles a nose. The nose of the face is actually formed by a mountain called the Apennines. Under the nose we find the mouth. In the picture it looks an amazing round-shaped mouth. In real life sometimes resembles a friendly smiling mouth.

Oort Cloud Facts

The Oort cloud around our solar system

Recent astronomical discoveries reveal a fascinating structure within our solar system. It consists of three zones. (Four if you also consider the Sun as a zone.) It is in the center of the Sun surrounded by a zone of four ‘Earth-like’ planets. These are the planets Mercury, Venus, Earth and Mars, which all consist of a dense, rocky substance. Around it is the asteroid belt; a disk with rocks of various sizes. Outside the zone are the so-called ‘Gas Giants’: Jupiter, Saturn, Uranus and Neptune. (Giant planets with relatively sparse composition.) Their territory is again surrounded by the Kuiper Belt; a huge disc consisting of chunks of frozen gas. Some of these pieces have a planetary shape such as the dwarf planet, Pluto. Finally; the last zone, a thousand times larger than the zones mentioned above, the Oort Cloud.

oort cloud facts

The Oort Cloud

This hypothetical gas giant is a spherical cloud of comets surrounding our solar system. Its outer edge is about 50,000 astronomical units from the Sun. That is about 0.79 light years. (A light-year is the distance traveled by light in one year.) The Oort Cloud travels the Astronomical Unit; the distance between the Sun and Earth. That is about 150 million kilometers.

Trans-Neptunian Objects

The Kuiper Belt and scattered disc, two other reservoirs of TNCs (Trans-Neptunian Objects) within our solar system are, compared to the Sun, only one thousandth of the distance from the edge of the Oort cloud. The outer limit of the Oort cloud defines the cosmographic boundary of our solar system. This is the area which dominates the gravitational force of the Sun. Objects that this space will slowly be pulled towards the Sun and eventually end up in this area. In orbit, an object to a neighboring star or gas cloud will be drawn outside the area.

Constitution of Oort Cloud

It is thought that the Oort cloud consists of two parts. A spherical outer cloud and a donut-shaped disk or inner cloud. The latter is also called “Hill Cloud”. The objects in the Oort cloud consist largely of ices such as Water, Ammonia and Methane. Astronomers believe that the matter inside the Oort cloud originally formed closer to the Sun. However; it was forced apart by the gravity of the four giant planets orbiting around the Sun during the evolution of the solar system.

Origin of Comets

So far, there aren’t any direct observations of the Oort cloud. Nevertheless, many astronomers believe that it is the origin of many Halley-type comets. These are comets that can occur anywhere in the sky unlike Jupiter Family comets or former Centaurs. They are always seen on a path from the Sun to the Earth. Both the Oort comets, like the Jupiter Comets, probably arose from the original protosolar (disc-shaped) cloud. This came about 4.6 billion years ago.

Distant planets

There were four bodies discovered far beyond the Kuiper belt that might belong to the Oort Cloud. Only one of them has received a name. That is the dwarf planet Sedna, named after an Eskimo (Inuit) goddess. Sedna’s presence suggests an inner, donut-shaped disk in the plane of the Ecliptic. That is the imaginary path that all planets and other celestial bodies (other than Halley-type comets) orbit the Sun. The existence of the stable Hill Cloud may explain the lasting stability of the highly volatile and tenuous Oort cloud after billions of years.

Estimated Mass of the Oort Cloud

The estimated mass of the billions of objects in the Oort cloud is about five times the mass of Earth. In kilos that are a 3…followed by 25 zeros! It was previously thought to be about 380 Earth masses, but the increased knowledge about comets is significantly revised downwards.

How is a star born?

Birth of a star

The universe is a wondrous place where many processes, that defy all imagination,occur. One of these magical phenomena is the birth of a star. Born out of nebilas, a star is the end result of high energy; nuclear fusion.

Nebulas

Nebulas are huge interstellar gas and dust clouds, whose size can be many light years across. They are the birthplace of stars, containing enough cosmic dust to produce thousands of stars, like our Sun. Stars are primarily made up of two molecules, hydrogen and helium. Nebulas also contain larger, more complex molecules that are the reminants of old stars.  These stars violently explode creating what’s called a Supernova.

birth of a star

The importance of the gravity

Due to irregularities in the density of the interstellar gas clouds gravity at the height of these regions will play a free role. The gas molecules present are drawn closer to each other, causing them to lose their potential energy. This loss of energy results in an increase of the temperature.
As more and more gas molecules are drawn towards each other, the temperature will continue to rise. The huge gas cloud will eventually be broken down into smaller nebulae, each giving rise to the formation of a star.

The fusion

The particles are in the center of the gas clouds being pulled towards each other more than in the outer regions. This ensures that the entire cloud starts to rotate at an exponential rate. When the temperature reached in the core of the nebula 1727 ° C, the hydrogen molecules are split into hydrogen atoms. Finally, a rotating mass of gas with a huge temperature obtained, which constantly collapsing core. This early stage in the birth of a star is also known as a proton-ester. The further evolution of the ester is dependent upon the mass of the proton ester. Will protostars with mass can thus smaller than those of the Sun never reach the temperatures of fusion. These stars are called brown dwarfs. The temperature in the core will, however, if their mass is large enough, eventually increase to 10 million degrees Celsius. At this temperature, there occurs a nuclear fusion of hydrogen into helium and deuterium. This nuclear fusion reactions transmit energy which creates a gravitational pressure to the action of the force of gravity on the star counteracts. From As a result, there will be an equilibrium between the gravitionel pressure and gravity, in which the star is fully balanced. When the star has entered this state of balance, they will be mass depending evolve. Will be small stars that hydrogen is gradually merge as much slower to evolve than massive stars.

How long the star will stay alive?

The lifetime of an ester depends on the amount of gas that are present in the core. When these gas supply runs out, there is no fuel for the various nuclear fusions more. Consequently, there will be an end to the balance between the gravitational pressure and gravity, and the star will collapse.

Is outer space a perfect vacuum?

Outer space (also called just space) is all the space in the universe beyond Earth and its atmosphere. It can be simple stated that in outer space there is no air (atmosphere) and it is a vacuum (empty of matter) however, it is not actually empty. Space contains tiny particles called cosmic dust and elements like hydrogen and helium atoms. The vastness of space not having any beginning or end, has unimaginable distances between stars, planets and galaxies where the gas molecules density is so low that it is practically nonexistent. This is why astronauts have to wear special suits carrying air (oxygen) supply for breathing. Therefore, having a few hydrogen and helium atoms for every cubic meter (or per cubic centimeter) space is virtually a vacuum. The gravitational force of the attraction of large bodies (such as planets and stars) also cause gas molecules in space to pull closer to their surfaces thus, leaving the space between them virtually empty.

Hence outer space, is not a total vacuum or perfect vacuum but rather has the density and pressure of an almost perfect vacuum. A perfect vacuum has a gaseous pressure of absolute zero which in reality, does not exist. A perfect man-made vacuum has never been obtained and the most nearly perfect vacuum that exists, is in outer space where on an average it contains less than one molecule per cubic meter.

Is there sound in space?

This question may seems similar to a question already asked (Can you hear sound in space?) however, it is a very good question for the intellectually curious mind. So, is there sound in space? The answer is no. Sound is vibrations of air particles, so any “sound” that is heard in space has to come from other means such as from the electromagnetic spectrum and these waves are not sound. Light waves and radio waves (which are apart of the electromagnetic spectrum) in space, can be interpreted by radio equipment and then be translated into sound.

a star explosionIn space there are sound sources (e.g. explosion of stars, collision of asteroids, solar storms and so on) but they do not (and cannot) travel to be detected as how we hear sound here on Earth. Space being an almost perfect vacuum is not an efficient medium for sound to travel and be heard by ears. However, sounds can travel by air in the spacecraft through the metal of the ship. You can hear sounds in the spacecraft only due to air particles inside.Technically, if you are in a spaceship and it explodes, you would hear it before you die due to the air particles in the ship. Likewise, if another spacecraft was to explode not far from your ship, objects flying from that ship would hit your ship sending sound waves through the ship’s structure by vibration. This vibration would then be passed on to the air particles in your ship thus, causing you to hear it. Also, the exploding ship would release gases that allow sound to travel along its part but, this would very quickly diminish since the gas particles would readily spread out in the vastness of space (losing its density). Therefore, sound would die very quickly over a very short distance and any sounds carried by the gases from the explosion, would still be too faint for you to hear it in your space ship. If it is possible for any sound to be detected it could only be detectable only by the most sensitive microphone and not the ear. So, strictly speaking, in this case it is possible for sound to travel a very short distance but all in all, space is silent.

How do Astronauts communicate in space?

In order for one to hear sound it must travel through air (gas particles) of which space has very few per cubic centimeter. Sound can only travel through a solid, liquid or gas. Space being an almost perfect vacuum does not allow sound to travel and be heard by the ears. Sound is vibrations of air particles, so any “sound” that is heard in space has to come from other means such as from the electromagnetic spectrum and these waves are not sound.

How do Astronauts communicateAs such, astronauts communicate with each other in space when they are spacewalking through the use of radio waves. Radio wave signal are sent to their headsets which then translates the signal into the form of sound . When receiving and sending message to earth it is sent in the form of radio waves which is then translated to sound wave (message) by a radio set. Radio wave is a part of the light spectrum called electromagnetic spectrum (see diagram below ) and is therefore a light wave. Light does not need a medium to travel and this, further explains why the Sun’s light travels through space to earth. Light waves are not sound waves.

Astronauts can however, talk to each other as if they were on Earth only when they are in their space ship. Here, there are enough air particles to vibrate and take the sound to their ear drum.

Electromagnetic-Spectrum

Why is the sky blue in the day and black at night?

blue sky1

During the day (daylight) the sky has a blue appearance because the Sun’s light (white light) is made up of rainbow of colors (red, orange, yellow, green, blue, indigo and violet) of different wavelength. This means, all these different colors of light combine to give you what is called white light.  When sunlight enters the Earth’s atmosphere, it collides with air particles that causes the scattering of sunlight around the sky. The light with the shorter wavelength is scattered more by this collision than light with longer wavelengths. In this case, violet light is scattered the most, but human eyes do not see this color very well. However, since the human eyes are more sensitive to blue light (the next most scattered visible color), you will see the sky as blue. This therefore means that the blueness of the sky is from the blue light that is scattered from the sunlight in the atmosphere which, then enters our eyes from all regions of the sky.

space - 1The black sky at night that shows you the moon, planets and stars is due to the absence of the Sun’s light. The overwhelming effect of the Sun’s light reacting with the atmosphere blacks out (conceal) the blackness of the sky (outer space). This means therefore that because there are no scattered light to reach the eyes of an observer during the night (to conceal the viewing of outer space) we get a clear (transparent) view of space, which is black. So, the sky is black during the night because it is revealing outer space.

It is also important to note that, the moon does not give its own light but reflects the light from the sun. This reflected light from the moon is not strong enough to have the same effect (of blotting out the view of outer space) as the Sun.

What are Shooting Stars?

There are many different sizes of rocks that can be found in space. As the Earth revolves around the Sun, it will be exposed to some of the rocks that come in its path. When these rocks collide with the Earth’s atmosphere (at great velocities), they begin to heat up due to air friction. Because of the high temperature produced from the air friction, they start to glow and then burn up. This is what we observe in the sky (at night) which appears to us as a glowing star moving across the sky. This trail of light is short-lived and vanishes in few a seconds. This also happens during daytime but we cannot see it because they are too dim in the sunlight. This glowing (burning) rock is called a meteor or what we commonly call a shooting or falling star. A meteoroid is that debris found outside the atmosphere. A meteoroid can range from the size of a grain of sand up to a boulder. Meteoroids are composed of stone, iron, or a mixture of stone and iron. If a meteor goes through the Earth’s atmosphere without burning up and hit the Earth’s surface (ground), it is called a meteorite. In other words, an incomingmeteoroid that survives its passage through the Earth’s atmosphere as a meteor and impacts the Earth’s surface, it is then known as a meteorite. Most meteoroids however burn up when entering the Earth’s atmosphere. Meteorites are of two types; stony and metallic.

shooting stars

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At certain times of year, several meteoroids collide with the Earth’s atmosphere. This happen when Earth goes through a region of space that contains a lot of rocks and dust. This debris come from the passage of a comet that breaks up as it comes near the Sun ejecting a lot of dust and chunks of rock in its path. If the comet’s orbital path intersects with that of Earth, then the swarm of rocks and dust scattered over the comet entire orbit will then collides with the Earth’s atmosphere. This event will result in what you called a meteor shower. Large numbers of meteors observed in a particular part of the sky are named for the constellation in which they appear to originate. For example, the Aquarids seem to come from the constellation of Aquarius (July 15- August 15 – Delta Aquarids), Leonids will appear to originate in the constellation of Leo (November 15-20), the Perseids from Perseus (July 25 – August 18) and the Orionids from Orion (October 16-27). Scientists (astronomers) used the name of the constellation it appears to come from to name them for easy reference. Meteor showers occur on about the same dates each year.

Therefore, a falling star or a shooting star has nothing whatsoever to do with a star. It is just another name for a meteoroid (interplanetary debris) that burns up as it enters the Earth’s atmosphere. That is, air friction vaporizes them into the white-hot streaks of light. This visible path (streak of light) of a meteoroid is a meteor. Thus, shooting stars or the falling stars are meteors.