September 19, 2022
The James Webb Space Telescope was named after a former administrator who worked for NASA in the 1950s and 60s and oversaw the Apollo program. It is the world’s largest and latest orbiter telescope with a mission length of 5 to 10 years. It cost a whopping 10 billion USD and took about 25 years …
October 20, 2020
In order to answer this question, we first need to define what we mean by up and down in space. And also acknowledge that the only reason ‘up and down’ exists as a binary is because we created them as humans.What is up and what is down?Since we are held to the surface of the …
October 20, 2020
The sun will never run out of oxygen because it does not use oxygen in its process in the first place.What does the sun burn then?The sun does not burn thanks to a chemical combustion such as the flame fed by oxygen. The sun carries out nuclear fusion instead of using oxygen. The sun is …
October 20, 2020
The earth’s ocean tides are not just caused by the moon’s gravitational pull, they are actually also caused by the sun’s gravity too. We are led to believe that it is just the moon, but this is not the case.How strong does gravity have to be to affect the tides?The tides on earth are not …
October 20, 2020
To start with: the sun is not the center point of solar system. But the answer is more complicated than that. First, we have to define the center of our solar system, then we need to investigate why people believed the earth was the center instead of the ‘obvious’ answer of the sun, which is …
October 20, 2020
The quickest way to answer this question is to say that the stars are not actually fixed in space, they are in fact always moving. But we are also going to explain how astronomers know this and how stars are actually always moving. Since, you came here for an answer.But they always look so still!Yes, …
October 20, 2020
How to define a space movieWhen we talk about space movies, we can mean one of two things: movies that are simply set in space and science fiction movies. These are so different in that movies set in space can have the capacity to be incredibly accurate, but science fiction movies are designed to be …
October 20, 2020
What is the speed of light?The speed of light in a vacuum always travels at exactly 299, 792, 458 meters per second. This is the unit c in equations. This is the case from the moment of its creation, light does not need to accelerate to this speed, it is already going this speed from …
October 20, 2020
Although the question suggests that it is a fact that the Great Wall of China is visible from space, it actually is not visible to the naked eye from space. According to NASA themselves, the Great Wall of China is not even visible to the naked eye when in low-earth orbit. Yes, the Great Wall …
October 20, 2020
The real question should be: what is the speed of gravitational change propagation? This might be a little confusing at first, but this answer will help to make sense of the topic.Other questions that ariseSince this question is quite a big one to ask, there are also some other questions that it uncovers alongside it. …
October 20, 2020
The short answer is that there is no set limit that is rigid for a magnetic field strength. But some interesting things will start to happen when magnetic fields reach a high strength.How does a magnetic field work?A magnetic field will act in a way that exerts its force sideways onto a moving electric charge. …
October 20, 2020
Contrary to the suggestion of the question, a space ship would not stop when it runs out of fuel. Even though there are objects in space like gas, dust and particles, they are in such low concentrations and so spread out that it is highly unlikely that a space ship would come into contact with …
October 20, 2020
To answer this question, we first have to think about how we actually define what a planet is. In space we have different ways of characterizing the astronomical bodies, and of differentiating them from one another.Is there a way to define what a planet it?In science, numbers play the largest role because they are exact …
October 20, 2020
Although it is true that the universe is expanding at a rapid rate, this expansion of the universe does not affect our galaxy in the ways you might think.How galaxies are affected by universe expansionOur galaxy is made up of astronomical bodies, all of which orbit other objects and have a set path that has …
October 20, 2020
To begin with, there is no amount of water that you can throw at the sun to ‘put it out’. Throwing water on the sun would actually make the sun burn even more.Isn’t the sun like a giant fire?The sun’s process is nuclear fusion, not chemical combustion which means that it is not a regular …
October 20, 2020
Actually, the wind is not the only factor that causes ocean currents. It is true that the wind plays a role, but it is only a small one compared to some of the other variables involved. On top of this, the factors that we are about to explain, including wind, act in different ways on …
October 20, 2020
What is a photon?A photon is a particle of light. Or, more specifically, it is a particle that represents light. A photon will carry energy.Can a photon travel at the speed of light?Since a photon is a particle of light, this means that it does not need to accelerate to light speed, as it is …
October 20, 2020
To answer the second part of this question first: black holes do not suck everything in. Some objects can actually orbit black holes just like the earth orbits the sun: safely. This is possible because black holes have their own gravity just like our sun does, or like stars do in general. In fact, stars …
October 18, 2020
The basicsThe heart does not actually work on its own to pump blood all the way around the body, this is because there would be a high amount of pressure at the area of the heart and a significantly lower pressure at the extremities. So, imagine blood being pumped away from your heart to the …
October 18, 2020
The simple answer is no, gravity does not extend out forever. Although there is a theory that states that it does.Newton’s Law of Universal GravitationNewton’s law states that the force of gravity on one mass due to another mass will depend mainly on their separation. This separation is represented as r where the dependence is …
October 18, 2020
This is an example of a question that has been influenced by science fiction literature and movies that seem to warp the truth on things like this for entertainment. But also, the science itself can be confusing. This answer will debunk the incorrect beliefs that we hold and also explain why they are wrong.So, do …
October 18, 2020
The short answer is that you do actually weigh less at the equator than you do stood at the North Pole. This is the same for the South Pole too. But this answer will debunk some of the mystery surrounding the answer and delve deeper into why this is the case.Does your body change when …
October 18, 2020
Can you make a shock wave of light by breaking the light barrier just like supersonic airplanes break the sound barrier?The answer to this is twofold, because it can be answered both yes and no. It depends on the material that you are in.Can anything travel the speed of light?Yes, particles that are considered quantum …
October 18, 2020
To start with, your mass is not affected at all by the speed that you travel at. People tend to believe that objects gain mass as they travel at higher speeds, mainly because old textbooks and teachings have us believe that. But according to Einstein’s theory of Special Relativity, this is simply not true.So why …
October 18, 2020
It is true that a star can turn into a planet, but the star has to be a brown dwarf. There are multiple different types of star, all having different properties, but in order for a star to become a planet, it would have to have been a brown dwarf star.Brown dwarfs are stars?Normally, stars …
October 11, 2020
First of all, there definitely is a lot of gravity in space. Gravity is a force that is very prevalent in space, even if it is not strong everywhere. In relation to the surface of Earth, gravity is obviously weaker the further from Earth you go, but gravity is still there in space. Gravity can …
October 11, 2020
The sun never changes its temperature in relation to Earth’s seasons. Since it is literally a ball of fire facilitated by nuclear reactions, its surface stays hot all year round. The extremely high heat of the sun causes it to emit copious amounts of radiation in all directs from its spherical shape. Since the sun …
October 11, 2020
Conversely to the question, the moon is actually not that bright, especially when we compare it to other astronomical objects in space. The reason that the moon appears so bright in our night sky on earth, is because we are comparing the brightness of it to the object around us that are receiving absolutely no …
October 11, 2020
In a short answer: light is not in fact pure energy. It is, however, true that light has no mass. But the fact that light has no mass does not mean that light is pure energy. Light is actually made up of objects called photons. This can be compared to other fundamental quantum objects since …
October 11, 2020
On the contrary, gravity is actually the weakest force. This is true when it comes to the fundamental forces anyway. If you order the four fundamental forces from weakest to strongest, it would look like this: gravity, weak nuclear force, electromagnetic force, and the strong nuclear force. If we are to zoom in on two …
October 11, 2020
Thanks to gravity, the earth does fall. It is actually in a constant state of falling since it is in orbit around the sun. This gravitational pull that the sun has on the earth is useful since it stops earth from catapulting into space. Gravity means that objects are not just drawn to the thing …
October 11, 2020
The quick answer is that, according to observations made by astronomers, there is no edge to the universe. The universe is constantly expanding meaning that space spreads out infinitely in every direction. Galaxies and nebulas and stars fill out all of the space throughout this infinite universe. There are two observations that make this believable. Firstly, …
October 11, 2020
This is a complex question with an even more complex answer. But essentially there is no center of the universe according to current observations. If a center point were to exist, it would need to significant and special in a way that meant it was special to the whole universe collectively. So, this answer will …
October 11, 2020
The truth is, the planets in our solar system never actually line up perfectly. This is something that we think should happen because a lot of the artwork surrounding the solar system sees all of the planets in a perfectly straight line that is just not achievable for our solar system. We are led to …
October 11, 2020
To begin with, being ‘stuck’ in the night sky is not exclusive to the North star: none of the stars in the night sky actually move enough for our time measurements to comprehend. They will move over the course of millions of years, meaning we won’t see them move across the sky in our lifetimes. The …
October 11, 2020
Logically, there can be no darkness without the existence of light. Think of a bright day accompanied by the shadows that the sun casts when blocked by something like a streetlamp. Darkness is simply the absence of light, so it follows that it travels at the speed of light. The absence of light, or darkness, is …
October 6, 2020
In a short and direct answer: the sun’s light and color is white. You may have heard about the light spectrum that we can see with the human eye being white light. This is because they all come together to form white light. Since we can see the range of seven colors of light in the outside …
October 5, 2020
There are not really any solidly compelling pieces of proof that show that a full moon can make people crazy and commit crimes. But the myth surrounding this claim is greatly interesting. Since the term ‘lunacy’, a word we use to mean ‘mad’ or ‘crazy’, is derived from ‘Luna’ meaning ‘moon’, the origins of this idea …
October 5, 2020
We cannot use gravity as an infinite energy source. This is because gravity cannot actually be used as an energy source at all. Since gravity is a force, it is not an energy source. Energy and force are two different things and should not be confused. Where energy can be described as being a property in …
October 5, 2020
Although it is true that light has no mass, it does in fact carry energy. This answer is a little more complex than that simple statement though and may require you to have a little basic knowledge on Einstein’s theory of special relativity: the theory that can explain how space and time are linked. E …
October 5, 2020
The short answer is that it the expansion of the universe is not what makes space a vacuum. What we call a vacuum in outer space is actually caused by gravity. And when we say, ‘outer space’, it refers to the whole area of space that is not considered the atmosphere of planets or stars. And …
October 5, 2020
A lot of scientist will say that astrology does not ‘work’. But believers in astrology will tell you that it is real and that it does work. The real answer is that it depends what you mean by the word ‘work’. Both answers and groups of people are technically right, depending on their definition of ‘work’. …
October 5, 2020
The short answer is that astronomers have been seeing violets shifts occur a lot, because they actually happen all the time. But we call them blue shifts. The way we can tell the type of shift is by looking at the light that a star emits. Obviously this color is relative to the colors that we …
October 5, 2020
In principle, yes, time does go faster at the top of a building compared to the bottom. This is because time will go faster the further you are from Earth’s surface when you compare it to someone who is on the surface of Earth still. This is something that Albert Einstein predicted when he developed his …
October 5, 2020
The short answer is that sound does not travel in space at all. Since sound is received by our ears in the form of vibrating air and there is virtually no air in space, there is nothing to vibrate to make a sound. You could even imagine the loudest sounds you can think of, like a …
October 3, 2020
When I took physics in college, I seem to remember a formula that related the wavelength of light to its energy. Could the wavelength of a photon of light be altered by a loss of energy, however small, over its path through intergalactic space? If that were true, looking at a trip of millions / …
October 3, 2020
Thanks for your interest in our profession! It is exciting that you picked Astronomy for your report. Here’s a list of answers to your question written by some of my colleagues at the University of Santa Cruz: Astronomy as a Career. I’d like to add that as an astronomer, there are two main paths to the …
October 3, 2020
Light travels about 186,000 miles/sec. in a vacuum. Why this speed, and not some other speed? This is a great, simple, question that touches the heart of modern physics. The simple answer is that we don’t know. The speed of light, c, is one of the “constants of the Universe” that we can measure, that …
October 3, 2020
Does a sunset in the west and a moonrise in the east ever happen at exactly the same time? Yes, a sunset and moonrise can occur at about the same time. Specifically, it occurs on the night of a full moon! Let’s convince ourselves of why this is… Whenever we think about sunrises/sunsets in relation …
October 3, 2020
What are the degree requirements and verification required to become an astronomer? There are now diverse career trajectories for astronomers inside and outside of academia. Please check out this website compiled by the American Astronomical Society to see what other jobs are available to astronomers. To answer your question I will focus on a traditional career track …
October 3, 2020
Would the constellations we see from Earth look any different from other planets in our solar system? In other words, would the “Big Dipper” still be recognizable as such? Great question! The stars that we see and that make up the constellations are distributed in three dimensions more like blueberries in a muffin than like …
October 3, 2020
I’ve heard multiple sources say the sun is white, that it just looks yellow because the Earth’s atmosphere is scattering the blue light. I’ve heard in other places that the sun is yellow because of its position in the Hertzsprung-Russell (H-R) Diagram. Which is it? It can’t be both yellow and white at the same …
October 3, 2020
I understand stars are millions of light years away and it takes a long, long time for the light of say a star exploding to reach us. We have pictures of stars exploding 50 years ago. Why are those stars still exploding? Do they explode in slow motion?? Also, why don’t we see galaxies turning? …
October 3, 2020
That’s a very interesting question, and one that can often be very difficult to answer when getting deep into the details, but I’ll try and do a quick “back-of-the-envelope” calculation for you and mention when these tricky little details might become important and change my answer. Here is the basic problem to solve. The Sun …
October 3, 2020
I read that Betelgeuse is shrinking. Is it true, and will there be any consequences? Betelgeuse is a star very often studied by astronomers. Before answering why Betelgeuse is shrinking, let’s explain how to keep a star in a stable state. To do that, two forces must be in equilibrium: gravity, which pulls inward and tries …
October 3, 2020
Do single stars tend to rotate in the same direction as the Sun and/or the Galaxy? This is a more technical question, so I am going to give a more technical answer, but first the simple answer. No, the rotation of a single star is not aligned with the galactic rotation because there are more …
October 3, 2020
Thanks for the great question! Many people get confused about these two terms as you do. Hopefully I can help clarifying the difference. The dictionary definition of “Twin” is a person or thing that is exactly like each other, or something containing or consisting of two matching or corresponding parts. Therefore, when an article says …
October 3, 2020
How can astronomers zero in on one single star for spectral analysis yet be sure they are not receiving light pollution from other stars in the field of view? Before the spectrum is taken, we are usually able to image the star field and we can also image the position of the slit, which lets …
October 3, 2020
I live in Dallas, where we feel lucky to see Jupiter and Saturn. Is it possible to see the Andromeda galaxy with the unaided eye when in dark sky country? It is, as you obviously know, a function of relative brightness. The darker the night sky, the dimmer the objects that can be seen. In, …
October 3, 2020
When I look up and see the Milky Way galaxy, am I looking towards the center of the galaxy or towards outer space? Tell me a good astronomy joke while you’re at it. That is a great question! In fact, you are generally looking into the DISC of the Milky Way galaxy. I’m sure you’ve …
October 3, 2020
If the Universe is expanding and all galaxies are moving apart from one another, why is it that the Milky Way and Andromeda will one day collide? Thanks for the great question! To get to the answer, we will need to look at which forces operate on small and large astronomical scales (distances). The two …
October 2, 2020
Given the recent discovery of the presence of liquid water on Mars, how likely do you think the possibility of terraforming is? (I know that part’s open-ended, but stick with me.) Can you postulate a method to begin colonization and terraforming simultaneously, or would humans have to wait the (presumed) hundreds—if not thousands—of years for …
October 2, 2020
Planet X (Nibiru) is supposed to whip around from behind the sun and near-smack us every 3600 years. Almost all of the scenarios I’ve seen on YouTube require a complete suspension of orbital mechanics as currently understood. What sort of bizarre cometary orbit would be required to keep a planetary body close enough to the …
October 2, 2020
Is Pluto still a planet? How can astronomers decide if Pluto is or not a planet? Thank you for your question. It is one that often comes up, and hopefully my response will clarify Pluto’s status. The short answer is no, Pluto is no longer a planet. It is now classified as a type of …
October 2, 2020
Approximately how long does it take for a planet to be born? Is a planet currently forming and if there is, what is its name? To answer how long it takes for planets to form, we first need to have a look at how planets are formed. The formation of planets is very closely related …
October 2, 2020
Is it true that there is a policy to not send probes anywhere that conditions might support life? To my knowledge, there is no policy that explicitly prohibits sending a probe to potentially habitable extraterrestrial environments. Mars is a prime example, and probes have been sent there for decades now. It will be something similar …
October 2, 2020
Is Jupiter a failed star? I study how stars and planets form, which is a big part of the ways that Jupiter both is and isn’t like a star. We can consider Jupiter to look somewhat like a “failed star” because it actually has a chemical composition that is very similar to the Sun. Jupiter …
October 2, 2020
e most mornings, and I notice and understand how over the course of a year it rises in a different area on the horizon. These position changes having to do with the Earth’s tilt and rotation around the Sun. I also get to see the moonrise and its position change on the horizon, much like …
October 2, 2020
Is there a way to provide a magnetic field for Mars? Would one even be needed to keep an atmosphere on Mars (if an atmosphere could be thickened on Mars somehow)? It would be a shame to build up an Earth-like global warming on Mars to release its carbon dioxide into its atmosphere, only for …
October 2, 2020
What is the evidence that early astronomers used to show that the Earth is turning on its axis (or was it a growing understanding)? That’s a great question! Some of the early Greeks proposed that the Earth rotated on its axis to explain the apparent daily motions of the Sun and other stars in the …
October 2, 2020
About 100 tons of cosmic dust falls on the Earth everyday, and this has been happening for billions of years, making the Earth heavier. Why doesn’t this cause our orbit around the Sun to change? The orbit of the planets is determined by the total mass in the system, and the dominant mass is that …
October 2, 2020
The New Horizons eclipse photo of Pluto shows the atmosphere as a blue ring, while a similar picture of Earth would show ours with a red hue. What causes the difference since they both have a nitrogen atmosphere? Thank you for your question. It’s a good one! You are correct in that the primary constituent …
October 2, 2020
If the collision hypothesis about the formation of the Moon is correct, why is there no ring of debris around Earth? Surely the residual debris were not all swept up by the gravity of the Earth and the Moon. The collision hypothesis for the formation of the Moon (also known as the Giant Impact hypothesis) …
October 2, 2020
Is there public domain software that can calculate the trajectory of a spacecraft using a model of the solar system (that includes planets and moons)? Is it feasible for a group of high-school students to develop such a model for a fun (non-school, non-graded) project? The idea is to develop a model that would determine …
October 2, 2020
Why does only one side of the Moon face the Earth? Synchronized rotations would not last so long. There must be some force holding this pattern in place. Could it be that the center of gravity of the Moon is not in the middle of the Moon? One side of the Moon always faces the …
October 2, 2020
Seeing the Earth circles the sun and our Moon circles the Earth, why would a comet or asteroid, passing closer to Earth than the Moon, maintain its orbit and not get captured into Earth’s orbit? The reason, quite simply, is one of speed. The comet or asteroid is moving too fast to be captured into …
October 2, 2020
What proof do you have that planets are made from gas and dust? The main way we study what planets are made of is by looking at their birthplaces around other stars. Planet formation happens in what are called “protoplanetary disks”. These protoplanetary disks are made of material leftover from the formation of the central star. …
October 2, 2020
Does a sunset in the west and a moonrise in the east ever happen at exactly the same time? Yes, a sunset and moonrise can occur at about the same time. Specifically, it occurs on the night of a full moon! Let’s convince ourselves of why this is… Whenever we think about sunrises/sunsets in relation …
October 2, 2020
The way dark energy is normally measured is by mapping a large number of galaxies at specific redshifts. At this point, cosmologists have models that point to a specific redshift range where dark-energy started dominating the structure of the universe, so the goal of HETDEX and other dark-energy experiments is to map a large number of galaxies around …
October 2, 2020
What is the “hierarchy” of structures in the Universe? it seems that we have moon, then planet, then planetary system, then Galaxy, then maybe “several missing” in the hierarchy?, then universe. How many “several missing” structures would there be? And would all of them just be considered clusters within clusters? Or is the “galaxy” structure …
October 2, 2020
Are astronomers convinced that dark matter is the answer? Is it likely that there is a simpler alternative theory to help explain why general relativity fails at galactic scales? I will answer the second question first: no. All the simpler alternatives have been tested and they fail to explain all the observations. It is very …
October 2, 2020
In the November/December 2015 edition of StarDate Magazine, I quote Merlin as follows, “Astronomers see the earliest galaxies as they looked about 13 billion years ago. Since the time when those galaxies emitted the light that astronomers now detect, though, space itself has expanded, so the galaxies are now 48 billion light-years away.” If those …
October 2, 2020
If X-ray and radio beams can emit from black holes and the like in interstellar space, can lower frequency waves on the middle to low end of the spectrum be emitted from high-powered beams on Earth and then detected by telescopes – like a sub pinging to its target – in order to search for …
October 2, 2020
Can light travel without a carrier such as a gravitation field? Light does travel via a carrier, in the same way gravity does. If we think about light as a continuous phenomenon, this carrier is the electromagnetic field, just as gravity is “carried” by a gravitational field. If we think about light as a particle, then …
October 2, 2020
Based on the 2001 WMAP results, the Universe is flat with a 0.4% margin of error. But what exactly are the chances of the Universe being finite but unbounded? I know it’s an unanswered question in cosmology, but is there any estimate? The short answer to this question is that the Universe cannot be both flat and …
October 2, 2020
In the November issue of Scientific American, there is an article on the Dark Energy Survey, “Seeing in the Dark.” How is this survey similar to – or different – from HET-DEX (besides being in Chile instead of Ft Davis)? As the Scientific American article states, the five-year Dark Energy Survey (DES) will cover 5000 square degrees …
October 2, 2020
If a clock could survive in a black hole, would time stand still inside the black hole? What would space-time be like? The answer is kind of boring since we do not have physics to describe the inside of black holes, the official answer is “we don’t know”. We can speculate given what happens right …
October 2, 2020
Does the speed of light increase as it nears the event horizon due to the influence of a black hole’s gravitational pull? The short answer is no, the speed of light is always the same. To explore the subtle aspects of this question, we will consider it in the context of Albert Einstein’s general theory of …
October 2, 2020
Does the degenerate matter inside a black hole have a temperature, or is it so compact it’s functionally at absolute zero? Also, if event horizon scales with mass, does matter inside the event horizon have a specifiable density? Thanks for a very intriguing question. The basic answer is that no one knows and that it …
