Tag Archives: Astronomy

The Space Between Planets

Have you ever really sat down to think about how much space there is in the universe? It’s pretty inconceivable, but there are some useful tools that can help put things in perspective. You’ve already seen a scale model of our solar system by mass, so here is a model of the space between our planets that can fit in your pocket!

planets

What you need:

  • Long strip of paper
  • Marker
  • Brain

First, cut a strip of paper long enough that it roughly spans the distance of your arms. Then, have a marker handy to be ready to indicate where each planet will lie.

  1. Label one end of the strip as the sun and the other as Pluto/Kuiper belt.
    1. This will show the full distance between the sun and the outer reaches of the solar system.
  2. Fold the paper in half and crease it. That line is for Uranus, it is roughly halfway between Pluto and the sun!
  3. Fold it in half again (it should now be in quarters). The crease between Uranus and Pluto is for Neptune.
  4. The crease that is between the sun and Uranus is for Saturn.
  5. Now fold the sun to Saturn and mark Jupiter in that crease.
    1. We have completed all of the gaseous outer planets, meaning that all that is left are the rocky inner planets, which fit between the sun and Jupiter!
  6. Fold the sun to Jupiter and label it as the asteroid belt, the area in our solar system where some of the largest known asteroids live.
  7. Now fold the sun to the asteroid belt. This is where Mars goes.
    1. We will complete the remaining three planets in the last step.
  8. Fold the sun to Mars, then fold in half again. Closest to the sun is Mercury followed by Venus, then Earth.

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Take a look, roll it up, and there you have it! A basic scale model of the distances between the planets of our solar system that can fit in your pocket. Would you have been able to guess how much space there is relatively between our planets? Did any of the spacings surprise you?

Written By: Mimi Garai

The Geminid Meteors

Nothing is more exciting than looking up and seeing a shooting star streak across the night sky. But we all know it’s not really a star falling from the heavens, but rather a giant ball of rock, ice and dust skimming through the atmosphere.

This December we will be able to witness one of the most famous and spectacular meteor showers of the year. The Geminid Meteors will be in view between December 4th and December 16th. However, it will peak on the night of December 13th at roughly 10:00 PM, with the possibility of sighting about 120 meteors per hour.

meteors

Unlike most other meteor showers, these meteors don’t come from a comet flying through Earth’s atmosphere. Instead, they come from the asteroid 3200 Phaethon.

meteors 1Due to 3200 Phaethon’s highly elliptical orbit and maximum distance from the sun, takes about 1.4 years to orbit it. It has a debris trail in orbit and once a year, Earth runs into this dusty path, which intersects our planet’s path through space. It gets extremely close to the sun, only 13 million miles from it (Earth is about 93 million away from the sun).

Unfortunately, December’s supermoon may wash out all but the brightest meteors. But, facing south can be helpful to view them, since this is where they appear to emerge from. With or without the supermoon be sure to check it out, it’ll be a sight worth seeing!

Written By: Mimi Garai

A Planet Size Comparison

A planet is an astronomical body orbiting a star or stellar remnant that: is massive enough to be rounded by its own gravity, not massive enough to do fusion, and has cleared its neighboring region of planetesimals.

Our star (the sun) has 8 planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Though these planets share a common place in the Universe, they are vastly different in composition, temperature, distance from the sun, and size.

planet

But how different are these sizes? To demonstrate this we can use a 1 pound chunk of clay. Roll it out into as symmetrical a log as you can. Cut it into 10 equal pieces.

Jupiter, the largest planet in the solar system, takes seven of those pieces, 70% of the solar system by mass (excluding the sun). Saturn, the second largest planet, will take two of the remaining chunks, 20% of the mass of the solar system. This means that the last 10% of mass of the solar system is the six remaining planets.

planet roll

Roll out the next chunk and cut it into ten more pieces. Uranus and Neptune are the next largest planets, the get 4 and 5 pieces respectively. The last four planets are the inner rocky planets. Earth and Venus are considered to be “sister planets”, they are roughly the same size and will get 5 and 4 pieces of the remaining clay. The last tiny chunk should be rolled out and cut into three pieces this time. Since Mars is larger than Mercury, it will get two of the pieces, and Mercury will get the last one.

planet model

There you go! A clay model of the planets in our solar system by mass. Try to test your friends, family, students, or teachers to see if they can get the scale right.

Written by: Mimi Garai

Look up and Constellations

A constellation is a group of stars that are considered to form imaginary outlines or meaningful patterns on the celestial sphere. They typically represent animals, mythological people, gods or creatures. There are 88 modern constellations, but just because those are the ones that are recognized doesn’t mean that one you make up is less valid.

The stars that constellations are comprised of are not necessarily stars that are near each other. So how do they appear that way? It’s all about perspective.

constellations

Take for example, The Big Dipper, an asterism in Ursa Major. An asterism is a smaller part of a constellation, usually with more noticeable stars. The Big Dipper is composed of seven bright stars: Alkaid, Mizar, Alioth, Megrez, Phecda, Merak, and Dubhe. Together, they appear to be in the shape of a spoon (use your imagination). However, they are all different distances away from Earth as well as from each other. Their distances from Earth respectively are roughly: 104 ly, 78 ly, 82.5 ly, 80.5 ly, 83 ly, 79.5 ly, and 123.6 ly.  

constellations gif

But if you simply change your perspective, or location from which you’re looking at them, then the picture changes! Unfortunately, since we are all on Earth, our perspective can not move enough to make a big difference.

Written by: Mimi Garai

Looking Back At Cassini

NASA’s Cassini orbiter will be ending its mission with a grand finale dive into Saturn’s atmosphere on September 15, but it’s accomplished so much in its nearly 20 years of operation.

When it was first launched on October 15, 1997, it was the first mission to be an in-depth study of Saturn and its moons. As a part of that mission, it discovered and studied the hexagonal hurricanes at Saturn’s poles, seen above. It also determined that Saturn’s rings were a dynamic feature instead of just a static disc of gas and dust and imaged the first large structures within the rings themselves. Of the large structures it imaged, it actually discovered six moons: Methone, Polydeuces, Daphnis, Anthe, Aegaenon, and S/2009 S 1; and may have discovered a seventh. However, it increased our understanding of several of Saturn’s moons we had already discovered.

cassini

Image credit: Space Engine

Saturn’s moon Iapetus’ two-tone surface had been a mystery to astronomers for some time, but we now know the answer to this problem thanks to Cassini. As Iapetus spins, ice on its surface sublimates (or transitions directly from solid to gas) on the dark side and deposits on the light side.

cassini 2

Image credit: NASA, ESA

It had been known for some time that Saturn’s moon Enceladus was covered in ice, but Cassini made a startling discovery: geysers. Jets of water and ice shooting out from the surface of Enceladus, actually forming a layer in the rings of Saturn. This discovery may not seem important at first, but those geysers suggest liquid water beneath that icy crust, and liquid water is the key to our search for life outside this planet.

cassini 4

Image credit: NASA, ESA

Possibly the biggest accomplishment of the Cassini mission was actually done by the attached probe: Huygens. The Huygens probe became the first to land on a moon in the outer Solar System when it landed on Saturn’s biggest moon: Titan. Titan’s atmosphere and size had led astronomers to believe there to be lakes of hydrocarbons, organic molecules associated with life, dotting its surface. However, Huygens’ landing showed that while there are features like riverbeds, they have since dried up and the hydrocarbon lakes are limited to Titan’s poles.

cassini 3

Image credit: Space Engine

For it’s final leg of the mission, Cassini will dive into Saturn’s atmosphere on September 15, will burn up, and along the way it will be giving us even more information. Cassini will be measuring Saturn’s atmospheric composition and will be mapping its gravitational and magnetic fields.

From all of us at AstroCamp, thank you Cassini!cassini 5

Image credit: NASA, ESA

 

The Life and Death of Stars

Did you know that stars live and die just like other living things?…Okay, maybe not just like them. But they do have a beginning, middle, and end. All stars start out the same way, from a nebula. A nebula, otherwise known as a “star nursery”, is a cloud of gas and dust out in space. Nebulae will then start to clump up due to the massive amounts of gravitational pull. This clumping creates protostars, which are basically spherical masses of the gas and dust that are collecting even more gas and dust from the nebula.

stars 5

Once the gravity of the protostars becomes great enough, the process of fusion will begin, turning the protostar into a star. A star is defined to be a self-luminous gaseous spheroidal celestial body of great mass which produces energy by means of nuclear fusion reactions. Fusion is the act of turning lighter elements into heavier ones which can only occur under great pressures.

Depending on the original mass of the nebula and protostar, a star can be of any number of sizes. For our purposes, let’s stick with an average sized star (like our Sun),  a massive star, and a supermassive star.

stars 4

stars 3

For a Sun-like star, once it has completed fusing hydrogen into helium it will become unstable and swell in size, becoming a red giant. As a red giant, it will have a thin outer shell of some hydrogen gas, and an inner core of mostly helium. Once the helium runs out, it will become extremely unstable and puff out it’s shells of hydrogen and helium, becoming a planetary nebula. One example of this is the Ring Nebula (M57). Left in the center is a white dwarf star, which is named so due to how hot and luminous it is. When the white dwarf radiates its energy away, it will fade, becoming a brown (or black) dwarf star.

stars 1

stars

For a massive and supermassive star: they will go through the fusion process, become unstable, puff out a shell, swell to a red supergiant, start the next round of fusion, and so on and so forth, creating heavier and heavier elements. Once the massive and supermassive star become extremely unstable they will go supernova. A supernova is the largest explosion in space, which is very bright and ejects most of its mass.

stars 6When this happens for a massive star, a neutron star will be left behind. A neutron star is a celestial object with very small radius (typically 18 miles/30 km) and very high density, composed mostly of closely packed neutrons. Neutron stars also tend to rotate extremely quickly and emit regular pulses of radio waves and other electromagnetic radiation, earning them another name, pulsars.For a supermassive star, it will follow the same path of a massive star, but with one key difference. Instead of leaving a neutron star behind after the supernova, it will leave behind a black hole. A black hole is simply a region of space having a gravitational field so intense that no matter or radiation can escape.

Supernovae create the heaviest elements in our universe, which are the building blocks to life as we know it. Without this constant cycle of creation and destruction, we would have nothing. So the next time you look up in the sky, be thankful to that glowing orb of incandescent gas and all of the gas and dust that came before it.

Gravitational Lensing

gravityMost of us have experienced using a lens in some way, whether it was using glasses, cameras, or our favorite, telescopes. A lens is a piece of glass or other transparent substance with curved sides for concentrating or dispersing light rays. They have the ability to bend light! Did you know that gravity can bend light in the same way? We call this gravitational lensing; when a large massive object, like a blackhole or galaxy, passes in front of our view of a distant light source and a distant galaxy. It bends the distant light in different ways, sometimes creating two or more images or creating an Einstein ring, a complete ring of the image.

 

gravity 1

The glass shape at the bottom of the stem of a wine glass, and looking straight through the glass has almost exactly the same optical properties as a massive galaxy or blackhole!

When you pass the glass over a light source or picture, it distorts the light into an Einstein Ring. This is one way Astronomers know about dark matter! According to Einstein’s theory of general relativity, the presence of matter (energy density) can curve spacetime, and the path of a light ray will be deflected as a result.

gravity 2

Written by: Mimi Garai

What’s So Special about the North Star?

The most famous star in the night sky is undoubtedly the North Star, also known as Polaris. It isn’t the brightest or most spectacular looking star, but it is nevertheless very important. Let’s take a look at why!

The image above shows the north star in the Idyllwild sky. As we know, the Earth is spinning. This is what causes the sun to rise and set and the stars to move across the sky. It is also tilted,  which gives us our seasons. If we were to draw a line through the axis that the Earth spins around, and then extend it over 300 light years past the North Pole, it would go right to the North Star!

Screen Shot 2016-06-06 at 8.56.38 AM

The motion of stars around Polaris from AstroCamp. Careful examination reveals that the North Star does move a tiny bit over the course of a night!

Because of this, it stays almost exactly in that spot in the sky all  night and all day, and thanks to its perch high above the North Pole, it always points the way North! This is really important for navigation, especially in the days before GPS devices, but it gets better!  If you were standing on the equator, Polaris would appear to be right at the horizon. From the North Pole, it would appear to be straight overhead. This means that using its height in the sky can do more than just point out the direction, it can also tell you where you are on the Earth!

north star

This shows how to find your location on the surface of the Earth using the position of Polaris. Image Credit: Fort Worth Astronomical Society

latitude

Interestingly enough, there isn’t a “South Star” because just by chance, there isn’t a bright enough star right above the South Pole! However, that won’t necessarily be like that forever! When a top spins on a tabletop, the end of it will move in a circle. This is known as precession. The Earth is basically a giant top in space, and it behaves the same way! This means that the North and South Poles won’t always point towards to the same spot in the sky! Over the course of 26,000 years, this will cause the North Star to change from Polaris to several other stars and back again.

 

Precession_animation_small_new

The Precession of Earth’s axis will cause the North Star to change from Polaris to other stars over the course of 26,000 years. Image credit: Wikipedia user Tfr000

Written By: Scott Alton

You Are Here: Our Place In Space

Spend a clear night outside and you might notice something strange about the sky: the stars migrate from horizon to horizon. It’s not quite as obvious as the sun’s motion, but it’s true. Our home star isn’t the only one that appears to rise in the east and set in the west.

NightSky1 (1)
Image credit: Pearson Prentice Hall, Inc. 2005.

The illusion that everything outside our atmosphere orbits around us results from our planet’s own spin. Only the points along our axis of rotation, the imaginary skewer Earth spins on, seem to stand still. It just so happens that a star lies on this line! Polaris gets its name because of its strange behavior. Unlike other lights in the sky, the North Star can always be found in the same place. As for other stars, the closer they are to our axis of rotation, the smaller the circles they seem to trace.

NightSky2

Polaris appears to stand still because it’s located along Earth’s axis of rotation. The farther a star is from that axis, the larger the circular path it appears to take from our perspective. Image credit: Peter Michaud (Gemini Observatory), AURA, NSF

Stargazing cultures throughout history have noticed this hierarchy of motion and canonized it along with the constellations themselves. One Greek myth places self-centered queen Cassiopeia in the sky near Polaris, where she’s doomed to dip her head in the ocean year after year, never fully disappearing below the horizon. She’s a circumpolar constellation, one that circles Polaris closely. Farther from Earth’s axis of the rotation, tracing more generous loops in the sky, Cygnus the swan dives in and out of sight with the seasons, nobly trying to rescue a drowned friend.

NightSky3

Dark summer skies treat stargazers to one of the most striking sights to slice through the night: the main belt of the Milky Way Galaxy itself.

It’s a grand cosmic coincidence that there’s anything visible along our rotational axis at all. The night sky is mostly empty space. A typical star apparent to the naked eye has an angular diameter in the ballpark of 0.01 arc-seconds. In the whole world, the average human eye can detect 9,096 individual stars. This means that resolvable stars take up less than one millionth of one percent of our view of the universe. It’s astonishing that a stellar signpost happens to hang out in one of the two spots that don’t seem to move. What’s more, the North Star hasn’t always held its convenient position, and it won’t stay there forever. Our axis of rotation moves slowly over time. As it moves, it points to different patches of sky. Luckily for humanity in the Northern hemisphere, the axis has pointed to a guiding star through the time in history when we’ve learned to navigate.

Written By: Caela Barry

The Greatest Telescope That Almost Wasn’t

Why put a gigantic telescope in space? It’s a common misconception that Hubble was placed in orbit to be closer to the stars. Really, the difference in distance between our planet’s surface and low Earth orbit is negligible compared to how far away Hubble’s research targets are. The great advantage of a space telescope is its location outside of our atmosphere.

Light from faraway objects is distorted as it passes through the air on the way to ground-based telescopes. The universe looks much clearer with no atmosphere in the way. When Hubble launched in 1990 it was expected to deliver incredibly crisp images, hubble_in_orbit1but the school-bus-sized satellite’s first pictures were blurry. Something had gone terribly wrong.

Painstaking analysis by engineers on the ground revealed the source of the blur: spherical aberration. Hubble’s massive primary mirror, supposedly the most precise optical device ever created, had been meticulously ground into slightly the wrong parabolic shape, the result of a faulty testing mechanism. The mirror was off by about 1/50th the width of a human hair– a tiny error with massive consequences.

With hefty research expectations, billions of dollars, and NASA’s reputation on the line, project scientists snapped into action. A backup version of the Wide Field Planetary Camera, the instrument that would go on to produce Hubble’s most iconic images, was retrofitted with corrective optics. An ingenious contraption of moving mirrors was devised to refocus light from the primary mirror as it entered four other detectors. All this was designed and assembled on the ground, 347 miles below the faulty hardware. The math had to be perfect.

Thornton4thEVAKathryn Thornton on the 4th EVA of STS-61. Credit: NASA

Seven astronauts undertook an audacious mission to repair the giant scope. The STS-61 crew completed a record-setting five back-to-back spacewalks for a total of over 35 hours of EVA time. Their work was a resounding success. Hubble had been redeemed, and NASA vindicated.

Hubble Servicing Mission 1 stands today as a masterpiece of engineering, determination, and teamwork. It corrected the vision of humanity’s most powerful eyes on the cosmos, clearing the way for decades of compelling imagery and game-changing research.

Screen Shot 2016-04-24 at 12.11.41 PMHubble’s unprecedented depth of field allows scientists to peer into the early history of the universe. Credit: NASA

Today, the space telescope addresses fundamental questions about the age and nature of the universe. Its stunning documentation of faraway phenomena brings the wonder of space down to Earth. STS-61 narrowly salvaged public confidence in America’s ability to effectively explore space by turning Hubble’s story from one of crushing defeat to one of redemption.
Diagram source http://hubblesite.org/the_telescope/hubble_essentials/index.php#work ; all other images cred NASA

Written By: Caela Barry

WELCOME TO OUR ASTROCAMP BLOG

We would like to thank you for visiting our blog. AstroCamp is a hands-on physical science program with an emphasis on astronomy and space exploration. Our classes and activities are designed to inspire students toward future success in their academic and personal pursuits. This blog is intended to provide you with up-to-date news and information about our camp programs, as well as current science and astronomical happenings. This blog has been created by our staff who have at least a Bachelors Degree in Physics or Astronomy, however it is not uncommon for them to have a Masters Degree or PhD. We encourage you to also follow us on Facebook, Instagram, Google+, Twitter, and Vine to see even more of our interesting science, space and astronomy information. Feel free to leave comments, questions, or share our blog with others. Please visit www.astrocampschool.org for additional information. Happy Reading!

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