Would we see stars as ball shaped rather than star-shaped?

 Stars are pretty much perfect spheres.

The “star shape” isn’t “real” it’s due to diffraction. For telescopes - this happens due to the support structures holding up the mirrors - or the segmented mirrors in the case of telescopes that use multiple smaller mirrors rather than one big one.

With naked eye viewing, the effect is due to diffraction through your eyelashes (!!) - which is why the effect gets much bigger when you squint.

One cool “Pro-tip” to tell the difference between photos taken by Hubble and James Webb…is to count the number of “star bursts” around bright objects… these two photos are of the exact same patch of sky…

Aside from the fact that JWST is a whole lot sharper and brighter…

Hubble has four lines coming out of that bright star in the middle - which are due to refraction around the struts that hold it’s secondary mirror in front of the primary.

James Webb has six around the same star because is uses a bunch of hexagonal mirrors.

What are some of the most amazing facts about space?

 Some amazing space facts that I came across internet are as follow:

• If two pieces of metal touch in space, they will melt together and become one. It is something called “cold welding” or “contact welding”. This does not happens on earth because the atmosphere puts a layer of oxidised material between the surfaces which makes the welding processing impossible. This could seem like a big problem for satellites, space station in space but since the metals come from earth, they are already coated with the material.

• The sun is actually not yellow, it only appears yellow because of earth’s atmosphere. In reality sun outputs all colours in visible spectrum at almost equal intensity. Which means the true colour of sun is actually white.

• Stars can be weird. There is a star out there with the name Wise 1828+2650. But it’s not the name which is interesting but rather how cold it is. It is the coldest star ever found with a temperature range of -23 to -127 degree celsius. Another weird star is BPM 37093, the star core is made up of diamond (10 Billion Trillion Trillion carats to be precise). And Neutron stars are weirder, these stars are so dense that a single teaspoon of it’s material weigh over 100 Million Ton.

• In 2023, we might have a reality tv show on Mars. This if the Mars One project is successful which has a goal to set permanent colony on Mars. Out of over 200,000+ enteries, only 4 people will be selected who will be sent on and every step of the journey will be documented. Every 2 years additional colonist will be sent to set the further coloney (4 in 2023, 8 in 2025, 12 in 2027 and so on).

• Time on Earth moves faster than time in space. Time to melt your brain: all astronauts are time travelers. That's a fact! Why? Because the planet's orbit gives us Earthlings an extra second per week. It's called "time dilation" and it's one of the many contributions Albert Einstein made to the study of outer space.

• Outer Space smells unbearably awful. What does outer space smell like? It smells like it wants you to die. Imagine if you walked into a room that smelled like rum, sulfur, fried steak, burning metal, and raspberries.That's what outer space smells like. The universe is sending you a message: Go back to Earth - this place isn't meant for noses.

• There's a giant black hole hurtling through space at 3 million miles per hour. Let's not mince words: a supermassive black hole weighing in at millions (millions!) of times heavier than the sun is currently hurtling through space at roughly three million miles per hour. This particular black hole was ejected from its own galaxy and is roaming between galaxies, four billion light years away.

• Suppose a star is 100 light-years away from the Earth. Therefore, the light coming from the star (which carries its information) takes roughly 100 years to reach Earth. When we look at the stars, we are seeing them as they were years ago. If a star is 100 light years away, we are seeing it as it was 100 years ago, etc. If a star dies (goes nova), we won't know about it for the year-equivalent of its distance in light-years. Then, one day, we'll see a flash in the sky and we'll know that if it is 27 light-years away, the star died 27 years ago.

Source: Internet

Why don't we see other galaxies or even stars near us in space?

 By chance, mostly, we happen to be over 4 light years from the closest star and our galaxy isn’t that close to other galaxies. Beings on another planet around a different star in a different galaxy might have very different night skies, full of light, with little darkness in between objects from their point of view.

Even inside our galaxy, different worlds would see very different skies. A planet near the center of the Milkyway would have a sky crammed full of stars, separated by mere light weeks, instead of the average in our sector of 5 light years or so. We are much further from the center, about 2/3rds of the way out.

In our universe, galaxies are quite far apart. The light that reaches us on Earth has thinned out into very faint glows. Andromeda is pretty close to us as galaxies go. But it is still 2.4 Million light years away. If our eyes were sensitive enough we would see Andromeda clearly as the single dominant object in our sky. Here’s the Moon and Andromeda illustrated to show their relative sizes in our current sky:

Andromeda is actually way bigger than the Moon in our sky. But the light is too faint for us to really see it well. You CAN see it with your eyes if you know where to look, but it won’t look like much with just your eyes. Merely a faint smudge of light. And that is only possible if the sky is REALLY REALLY dark. The stars we see are much closer to us so their light is stronger, much stronger than the entire Andromeda galaxy from 2.4 Million miles away. Even a star 1000 light years from Earth is going to seem WAY brighter than the collection of stars in the Andromeda galaxy.

But nothing is permanent. Our sky will change dramatically over time.

The above shows a sequence of skies over Earth spanning several billion years. The merger will start in about 4.5 Billion years and the Andromeda and Milkyway will both be permanently distorted and altered. Eventually, we end up in some sort of elliptical galaxy with a sky blazing with stars.

But most of the universe is pretty uniform and spread out, with clumps of galaxies along strands of galaxy clusters and super-clusters. Because gravity clusters masses together and even causes galaxies to collide, the perception we currently have of everything being so far away won’t always be the case.

In the above Hubble image, you can see the results of two galaxies merging. The spiral arms get swept out in distorted shapes as the central regions of the galaxies try to merge into a more unified whole. This has happened countless times in our Universe and the above image is certainly not a rare case.

So regarding what we see in our sky, rest assured it won’t always be this boring. It just changes slowly, over billions of years.

I tend to think of our sky as boring. We live in the suburbs of our galaxy, nothing too interesting is clearly visible with our eyes. We need telescopes to look at the cool stuff in any detail. That said, even a modest pair of binoculars can reveal a lot of interesting objects and allow you to see way more stars than just your eyes can pick up on their own. There are a lot of stars in our sky. If we could see every star in our sky, it would look very different. But the light from more distant objects is typically weaker, so we just see black in between the brighter closer stars. But if we could just stand there, letting the weak photons from distant stars stack up in our eyeballs, we would see something like this:

The bright vertical band is the plane of our galaxy, and you can see dark dust lanes cutting through that light. More stars are visible here than you would see with your eyes. Photos like this leave the shutter open for several minutes to let the light accumulate.

So it is a matter of our perspective and the limitations of human eyes that give this impression that the sky isn’t full of light sources at night. We can reveal the truth of how full the universe really is by doing long-term exposures with cameras and by using telescopes. Of course, this is STILL a perspective. The universe is, in fact, mostly EMPTY. But if we can sample a large swath of the sky, we see a LOT of sources of light, most from objects in our galaxy.

If Andromeda is the closest galaxy to us, why have we not started exploring it yet?

 The nearest star beyond our own Sun is about four light-years away - or about 25 trillion miles. The farthest any man-made object has traveled from Earth (Voyager I) is currently 15 billion miles away. That is, Voyager I, launched in 1977, is about one sixteen hundredth of the way to the nearest star outside our Solar System … after nearly fifty years traveling in space. The Andromeda Galaxy is over 600,000 times as far away as that star. So that galaxy is about a billion times farther away than the most distant thing we have launched into space.

See all those stars in the photo below? They are all in our little section of the Milky Way galaxy. Every single one of those is many times farther away than Proxima Centauri (the nearest star I mentioned). That arrow locates the Andromeda Galaxy, which is about twice the size of our own galaxy, the Milky Way.

So maybe that’s the reason.

What are some of the most amazing facts about space?

 Scientists know about space in deep more then they know about oceans.

1. Space is around 13.8 billion years old. Scientists estimate that it would last another 5000 million years !

2. Footprint and tire tracks left on Moon will stay there forever, due to environmental conditions!

3. Sun makes a full rotation once every 27 days.

4. Chances of a person from earth being hit by space debris is 1 in 5 billion

5. There are approximately 200,000,000,000 stars in the Milky Way.

6. Largest star known to mankind is R136a1 which has mass of 265,320 times that of the sun !

7. Our moon is moving away from the earth at the rate of 4 cm per year.

8. Sun loses up to a billion kilogrammes per second due to solar winds.

9. In space the skin on your feet peels off!

10. Space is not that far away.

Space officially begins at the universal marker of the Karman Line. This invisible boundary is 100km above the Earth. In theory if you could drive your car upwards, you could be in space in less than hour.

Image source - astropics

What are some cool facts about space that most people don't know?

 

1. All planets and satellites are spheroidal??

NO. Satellites of Mars, Phobos and Deimos are are very uneven in shape. All the celestial object which stay in space for a long time turns spherical ( or ellipsoidal) due to effect of gravity ( nature loves symmetry). This might be because the satellites are captured from nearby asteroid belt which are not essentially spherical. Also satellite of neptune, Proteus is not symmetrical.

2. Hottest planet

Venus. Yes, though Mercury is closer to sun but its not the hottest, it is so because atmosphere of Venus contains high amount of carbon Di oxide. Which causes extensive green house effect (No wonder why women are from Venus).

3. High magnetic field of Jupiter

Jupiter's magnetic field is result if its gravitational forces. Jupiter mainly consists of hydrogen as main element. Gravitational force is so high here that hydrogen atoms fuse and show metallic nature. This causes high magnetic field.

4. Density of Saturn

Density of Saturn is 687 kg per meter cube. That's less than water. Hence it will actually float in water.

Saturn also has polar flattening of 0.098 which is highest in solar system. This basically means its very much away from being spherical. Or say it has very high equatorial buldging.

5. Rotation period of greater planets

Greater planets like Jupiter, saturn, Uranus and neptune have very low rotational periods. That is they rotate at very high speed. For example rotation period of Uranus is 0.720 days ( that is 72% of earths day) that is around 17 hours.

6. Not all natural satellites originated from their primary planet.

There are satellites of distant planets of our solar system ( like Nereid of Neptune) which were captured from outer solar system into Neptune's orbit.

It can be seen by their unusual orbit around the Neptune that they were captured.

7. Pluto has three satellites.

Yes our small and fallen brother has three satellites. More than us. One of which, Charon is quite big relative to its primary planet (10–15% of Pluto's mass). Other two are recently discovered ( 2005 P1 and 2005 P2).

8. Satellites of Jupiter.

Largest satellite of our solar syastem., ganymede is larger than mercury and Pluto. Its radius is 2631 km.

Thanks.

Source- my syllabus book, of course.

Image source- solar walk lite android app.

How do scientists measure and track something as far away as Voyager 1 in space?

 Great question!

Since the signals from the two Voyager spacecraft are SO faint at their current distances (e.g., Voyager 1 is an entire light-day from Earth), if we did not have a very good idea where they are, we would be unlikely to ever find them.

As to the instruments used to communicate with them, we rely on the NASA Deep Space Network, supplemented occasionally by the Very Large Array, the Very Long Baseline Array, the European Deep Space Network and the Japanese Deep Space Network.

Here is a rough diagram of the NASA DSN:

and here are pictures of the radiotelescopes at each location:

We are currently in the process of upgrading the dishes at each location:

What are some facts about space that sound false but are undeniably true?

 There are plenty of planets in our universe that allow what we think is impossible to become possible. Let's take the planet HD189773-b as an example.

When we see it from the outside, it looks like a beautiful planet, although that beauty hides a dark secret. The planet is located 64 light years from us and looks like it does because it is made of silicate particles, the winds scream at a speed of 2km/s or 7200km/h. But the most absurd thing about the planet is that it rains glass from the side! With the strong winds, the glass rushes at 2km/s. To understand it easier, if this were to occur on Earth, it would travel around the Earth in 5 hours and leave lots of glass behind.

What you are seeing is a unique image and it was captured by the James Webb Space Telescope

The most surprising thing about this new image, nothing short of sublime, is that it shows Neptune's rings as never done before. Oh yes, Neptune, like Saturn, also has rings!

It's been 30 years since these were first detected by NASA's Voyager 2 probe.

Webb's image quality now, however, allows it to detect even the fainter ones closer to the planet.

Neptune orbits in the remote, dark region of the outer solar system. At that extreme distance, the Sun is so small and dim that at midday it is similar to a dim twilight on Earth.

This means that there is very little visible light reflected by Neptune and is why it is so difficult to observe it with normal telescopes. Infrared images from the space telescope, however, can make us see it brighter because this type of light is reflected much more.

Compared to gas giants, such as Jupiter and Saturn, Neptune is much richer in elements heavier than hydrogen and helium. Clouds of methane and ice then appear, clearly visible as streaks and bright spots.

Just think, on this planet winds can exceed 1000 km/h!

Has anyone been in space and actually gone into or near a black hole?

 

Negative. The nearest black hole is believed to be in the V616 Monocerotis system, roughly 3,000 light years away.

The farthest that humans have travelled is to the moon. The black hole is 73,833,468,262 times more distant than the moon. At the velocity of the Apollo capsules it would take 80,472,276 years to reach that black hole.

If the dinosaurs had an astro program and sent an astronaut in the direction of that black hole, then he or she might well be just arriving there today.

What would happen to a dead body in space? Would it decompose?

NO, because without oxygen in space, there would be no decomposition for your body, as it would on earth, and it would not change much because there would only be chemical decomposition, perhaps a change in color, because there wouldn’t be oxygen for bacterial/fungal growth, which needs oxygen. Also, there would just be some chemical decay.

Since you were close to the source of heat, your body would mummify; otherwise, it would freeze. Should you be in a space suit, you would decompose until the oxygen supply was exhausted, at which point the bacteria and fungi responsible for decomposition would die.

In any case, your physical being would last for a prolonged period of time in space, where, without air, no weathering occurs. Your corpse could drift through space in the universe for millions of years.

What is the biggest myth about outer space?

 The biggest myth about outer space is in the name: Space.

Everyone thinks it’s empty.

I mean, why wouldn’t they? It says right there. Outer. Space.

So, why wouldn’t anyone think it’s anything but a vacuum!

Well, it’s not!

It’s teeming with a lot of stuff and activity. Just not as much as on Earth or any heavenly body, but enough to matter (no pun intended).

Image Credits: Stock photo, pixabay.

So, What’s Filling Up the Space?

Well, some of the things are familiar to us – atoms, dust, plasma, radiation, and so on.

Of course, when you leave the Earth and enter outer space, the matter density drops to negligible levels. There’s no question about that.

But, even in that seemingly vacuous space, there’s quite a bit of stuff, although not in any meaningful quantities for us to bother about it.

Think of it like this: On Earth, you have a high density of matter. As you fly into outer space, the density keeps dropping until you exit the atmosphere, when it hits negligible levels. Then, as you approach another planet, the density increases from negligible levels to a meaningful degree.

But, The Density Changes Too

Stars like the Sun have a kind of bubble or sphere of influence that can extend for light-years.

Within this halo, you’ll find an abundance of solar storms, coronal mass ejections, and other activity adding to that density.

So, matter density within this heliosphere is usually higher than what it is in the space between stars, which is even more sparse.

Things get really interesting between galaxies.

This is where matter density is the least. Lower than what’s in both interstellar and stellar systems’ space.

In short, intergalactic space is the least dense, followed by interstellar space within galaxies, and finally the stellar system space.

In general, there’s about 1 atom per cubic centimeter of interstellar medium. The intergalactic medium has an even lower average density of 1 atom per cubic meter.

And, There are Exceptions

So far, we’ve discussed only the regular baryonic matter that makes up the things we know – planets, air, water, life, etc.

But that’s not everything.

There’s the more exotic stuff you won’t easily find on Earth: cosmic rays, dark matter, neutrinos, and dark energy. Dark matter is present within galaxies, and sometimes, outside too.

And every square inch of space is bombarded with hundreds of billions of neutrinos per second, especially in stellar systems.

And the ever-present quantum fluctuations don’t relent just because you are in outer space.

Vacuum energy, or zero-point energy, pervades the space, even in regions with the lowest energy density.

In a Nutshell

Think of outer space as an extremely low-density region with a lot of activity happening in it.

It’s not some inert, empty vacuum. It’s bubbling with activity, especially within galaxies.