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Galileo - Blog Posts
Falling Into Jupiter
Twenty-five years ago, an object roughly the size of an oven made space history when it plunged into the clouds of Jupiter, the largest planet in our solar system. On Dec. 7, 1995, the 750-pound Galileo probe became the first probe to enter the gas giant. Traveling at a blistering speed of 106,000 miles per hour, the probe’s protective heat shield experienced temperatures as hot as the Sun’s surface generated by friction during entry. As the probe parachuted through Jupiter’s dense atmosphere, its science instruments made measurements of the planet’s chemical and physical makeup. The probe collected data for nearly an hour before its signal was lost. Its data was transmitted to Earth via the Galileo spacecraft, an orbiter that carried the probe to Jupiter and stayed within contact during the encounter. Learn more about the mission.
The Galileo probe was launched to space aboard space shuttle Atlantis in 1989
The probe consisted of a descent module and a protective deceleration module
The probe traveled to Jupiter attached to the Galileo spacecraft
The probe was released from the spacecraft in July 1995
The probe entered Jupiter’s atmosphere five months later on Dec. 7, 1995
Parachutes were deployed to slow the probe’s descent
The probe collected science data for 58 minutes as it fell into the planet’s atmosphere
The Galileo probe was managed by NASA’s Ames Research Center in California’s Silicon Valley.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Magnetospheres: How Do They Work?
The sun, Earth, and many other planets are surrounded by giant magnetic bubbles.
Space may seem empty, but it’s actually a dynamic place, dominated by invisible forces, including those created by magnetic fields. Magnetospheres – the areas around planets and stars dominated by their magnetic fields – are found throughout our solar system. They deflect high-energy, charged particles called cosmic rays that are mostly spewed out by the sun, but can also come from interstellar space. Along with atmospheres, they help protect the planets’ surfaces from this harmful radiation.
It’s possible that Earth’s protective magnetosphere was essential for the development of conditions friendly to life, so finding magnetospheres around other planets is a big step toward determining if they could support life.
But not all magnetospheres are created equal – even in our own backyard, not all planets in our solar system have a magnetic field, and the ones we have observed are all surprisingly different.
Earth’s magnetosphere is created by the constantly moving molten metal inside Earth. This invisible “force field” around our planet has an ice cream cone-like shape, with a rounded front and a long, trailing tail that faces away from the sun. The magnetosphere is shaped that way because of the constant pressure from the solar wind and magnetic fields on the sun-facing side.
Earth’s magnetosphere deflects most charged particles away from our planet – but some do become trapped in the magnetic field and create auroras when they rain down into the atmosphere.
We have several missions that study Earth’s magnetosphere – including the Magnetospheric Multiscale mission, Van Allen Probes, and Time History of Events and Macroscale Interactions during Substorms (also known as THEMIS) – along with a host of other satellites that study other aspects of the sun-Earth connection.
Mercury, with a substantial iron-rich core, has a magnetic field that is only about 1% as strong as Earth’s. It is thought that the planet’s magnetosphere is stifled by the intense solar wind, limiting its strength, although even without this effect, it still would not be as strong as Earth’s. The MESSENGER satellite orbited Mercury from 2011 to 2015, helping us understand our tiny terrestrial neighbor.
After the sun, Jupiter has by far the biggest magnetosphere in our solar system – it stretches about 12 million miles from east to west, almost 15 times the width of the sun. (Earth’s, on the other hand, could easily fit inside the sun.) Jupiter does not have a molten metal core like Earth; instead, its magnetic field is created by a core of compressed liquid metallic hydrogen.
One of Jupiter’s moons, Io, has intense volcanic activity that spews particles into Jupiter’s magnetosphere. These particles create intense radiation belts and the large auroras around Jupiter’s poles.
Ganymede, Jupiter’s largest moon, also has its own magnetic field and magnetosphere – making it the only moon with one. Its weak field, nestled in Jupiter’s enormous shell, scarcely ruffles the planet’s magnetic field.
Our Juno mission orbits inside the Jovian magnetosphere sending back observations so we can better understand this region. Previous observations have been received from Pioneers 10 and 11, Voyagers 1 and 2, Ulysses, Galileo and Cassini in their flybys and orbits around Jupiter.
Saturn’s moon Enceladus transforms the shape of its magnetosphere. Active geysers on the moon’s south pole eject oxygen and water molecules into the space around the planet. These particles, much like Io’s volcanic emissions at Jupiter, generate the auroras around the planet’s poles. Our Cassini mission studies Saturn’s magnetic field and auroras, as well as its moon Enceladus.
Uranus’ magnetosphere wasn't discovered until 1986 when data from Voyager 2’s flyby revealed weak, variable radio emissions. Uranus’ magnetic field and rotation axis are out of alignment by 59 degrees, unlike Earth’s, whose magnetic field and rotation axis differ by only 11 degrees. On top of that, the magnetic field axis does not go through the center of the planet, so the strength of the magnetic field varies dramatically across the surface. This misalignment also means that Uranus’ magnetotail – the part of the magnetosphere that trails away from the sun – is twisted into a long corkscrew.
Neptune’s magnetosphere is also tilted from its rotation axis, but only by 47. Just like on Uranus, Neptune’s magnetic field strength varies across the planet. This also means that auroras can be seen away from the planet’s poles – not just at high latitudes, like on Earth, Jupiter and Saturn.
Does Every Planet Have a Magnetosphere?
Neither Venus nor Mars have global magnetic fields, although the interaction of the solar wind with their atmospheres does produce what scientists call an “induced magnetosphere.” Around these planets, the atmosphere deflects the solar wind particles, causing the solar wind’s magnetic field to wrap around the planet in a shape similar to Earth’s magnetosphere.
What About Beyond Our Solar System?
Outside of our solar system, auroras, which indicate the presence of a magnetosphere, have been spotted on brown dwarfs – objects that are bigger than planets but smaller than stars.
There’s also evidence to suggest that some giant exoplanets have magnetospheres. As scientists now believe that Earth’s protective magnetosphere was essential for the development of conditions friendly to life, finding magnetospheres around exoplanets is a big step in finding habitable worlds.
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Solar System: Things to Know This Week
We've been up close and personal with Saturn for 13 years now, thanks to the Cassini mission.
From a tour of Saturn's many enthralling moons to an incredible view of Earth through its rings, the planet continues to captivate the imagination. This week, here are 10 things you need to know about our fascinating ringed neighbor.
1. Strange Sighting
When Galileo Galilei was observing Saturn in the 1600s, he noticed strange objects on each side of the planet. He drew in his notes a triple-bodied planet system with ears. These "ears" were later discovered to be the rings of Saturn.
2. Solar System Status
Saturn orbits our sun and is the sixth planet from the sun at an average distance of about 886 million miles or 9.5 AU.
3. Short Days
Time flies when you're on Saturn. One day on Saturn takes just 10.7 hours (the time it takes for Saturn to rotate or spin once). The planet makes a complete orbit around the sun (a year in Saturnian time) in 29 Earth years, or 10,756 Earth days. saturn.jpl.nasa.gov/news/2955/measuring-a-day
4. No Shoes Necessary
That's because you can't stand on Saturn—it's a gas-giant planet and doesn't have a solid surface. But you might want a jacket. The planet's temperatures can dip to -220 degrees F.
5. Few visitors
Only a handful of missions have made their way to Saturn: Pioneer 11, Voyager 1 and 2, and Cassini-Huygens, which is there now. Since 2004, Cassini has been exploring Saturn and its moons and rings—but will complete its journey on Sept. 15, 2017.
6. Saturn's Close-Up
This month is a great time to observe Saturn from Earth. Check out June's "What's Up?" video for a how-to guide.
7. Daring Dives
Saturn's spectacular ring system is made up of seven rings with several gaps and divisions between them. From now until September, the Cassini spacecraft is performing a set of daring dives every week between the planet and the rings. No other mission has ever explored this unique region before, and what we learn from these final orbits will help us understand of how giant planets—and planetary systems everywhere—form and evolve.
8. Many, Many Moons
Saturn has a total of 62 moons: 53 known moons, with an additional nine moons awaiting confirmation.
9. Curious Shapes
Saturn's moon Atlas looks like a flying saucer. See for yourself.
10. Would You Live on a Moon?
Saturn can't support life as we know it, but some of its moons have conditions that might support life. Ocean worlds could be the answer to life in space and two of Saturn's moons—Titan and Enceladus—are on that list.
Want to learn more? Read our full list of the 10 things to know this week about the solar system HERE.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Galileo’s notebook sketch of the Pleiades
Galileo Galilei 15th February 1564 - 8th January 1642
Falling Into Jupiter
Twenty-five years ago, an object roughly the size of an oven made space history when it plunged into the clouds of Jupiter, the largest planet in our solar system. On Dec. 7, 1995, the 750-pound Galileo probe became the first probe to enter the gas giant. Traveling at a blistering speed of 106,000 miles per hour, the probe’s protective heat shield experienced temperatures as hot as the Sun’s surface generated by friction during entry. As the probe parachuted through Jupiter’s dense atmosphere, its science instruments made measurements of the planet’s chemical and physical makeup. The probe collected data for nearly an hour before its signal was lost. Its data was transmitted to Earth via the Galileo spacecraft, an orbiter that carried the probe to Jupiter and stayed within contact during the encounter. Learn more about the mission.
The Galileo probe was launched to space aboard space shuttle Atlantis in 1989
The probe consisted of a descent module and a protective deceleration module
The probe traveled to Jupiter attached to the Galileo spacecraft
The probe was released from the spacecraft in July 1995
The probe entered Jupiter’s atmosphere five months later on Dec. 7, 1995
Parachutes were deployed to slow the probe’s descent
The probe collected science data for 58 minutes as it fell into the planet’s atmosphere
The Galileo probe was managed by NASA’s Ames Research Center in California’s Silicon Valley.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Falling Into Jupiter
Twenty-five years ago, an object roughly the size of an oven made space history when it plunged into the clouds of Jupiter, the largest planet in our solar system. On Dec. 7, 1995, the 750-pound Galileo probe became the first probe to enter the gas giant. Traveling at a blistering speed of 106,000 miles per hour, the probe’s protective heat shield experienced temperatures as hot as the Sun’s surface generated by friction during entry. As the probe parachuted through Jupiter’s dense atmosphere, its science instruments made measurements of the planet’s chemical and physical makeup. The probe collected data for nearly an hour before its signal was lost. Its data was transmitted to Earth via the Galileo spacecraft, an orbiter that carried the probe to Jupiter and stayed within contact during the encounter. Learn more about the mission.
The Galileo probe was launched to space aboard space shuttle Atlantis in 1989
The probe consisted of a descent module and a protective deceleration module
The probe traveled to Jupiter attached to the Galileo spacecraft
The probe was released from the spacecraft in July 1995
The probe entered Jupiter’s atmosphere five months later on Dec. 7, 1995
Parachutes were deployed to slow the probe’s descent
The probe collected science data for 58 minutes as it fell into the planet’s atmosphere
The Galileo probe was managed by NASA’s Ames Research Center in California’s Silicon Valley.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Eppur Si Mouve
Galileo fue condenado como hereje por la inquisición de la iglesia debido a su teoría heliocéntrica (los planetas giran alrededor del sol) ya que, según la iglesia iba en contra de la biblia, en la cual Josué detiene el movimiento del Sol y la luna sobre la Tierra, lo cual proponía la teoría geocéntrica de Aristóteles (los astros, incluido el Sol, girando alrededor de la Tierra) Galileo se tuvo que retractar y al final del juicio pronunció en latín: “Eppur Si Mouve” (Sin embargo, se mueve).
Sir Isaac Newton Hareket Yasaları
1666 yılında daha 23 yaşındayken Galileo ve Kepler’in çalışmalarında da faydalanarak “Hareket Yasaları” ve “Kütle Çekim Yasalarını” geliştirdi. Kalkülüs ve Cebir’in kurucuları arasındadır. 1687 yılında klasik fiziğin temeli olan hareket yasalarını 3 ciltlik “Principia” isimli kitabında anlatmıştır.
Newton, Galileo, Descartes hareketle ilgili fikirlerde bulunmuştur. 1600’lü yıllardan önce cisim hep durma eğilimi gösterir mantığı varken bu üç adam her şeyi değiştirdi. Cisimlerin aslında durmaya karşı bir direnç gösterdiğini savundu. Ve klasik fizik Newton’un ellerinde doğdu.
1.Yasa Eylemsizlik:
Eylemsizlikten ilk olarak Galileo bahsetmiştir. Newton kitabında eylemsizlik için “her cisim eğer üzerine etkiyen bir kuvvet tarafından durumu bozulmaya zorlanmazsa düzgün doğrusal hareketini ya da durma halini korumaya direnir” açıklamasını yapmıştır.
Sabit bir kuvvet uygulanan cismin kütlesi arttıkça, eyleme karşı direnci artar. Burada Newton 2.yasayla bir bağlantı kurmuştur. Zaten bu yüzden Descartes ve Galileo’dan hareket yasalarında çok daha önemli bir yerde görülür.
2.Yasa:
F=mxa formülünden de anlayacağımız gibi; cisim kütlesiyle ters , uygulanan kuvvetle doğru orantılı olarak ivmelenir. İvme gibi kavramları açıklamak için şuan da diferansiyel işlemler kullanırız. Aslında Newton’da bunların doğruluğunu kanıtlamak için Kalkülüs ve Cebir’i geliştirerek kullanmıştır.
3.Yasa Etki-Tepki:
Eğer bir cisme bir kuvvet uygulanırsa aynı şekilde cisimde bir tepki kuvveti doğurur. Kuvvetlerin çift olduğunu kabul ederiz bu yasayla birlikte.
Newton Hareket Yasalarını doğru kabul edebilmemiz için referansımız 1.Yasa olarak almamız lazım bu referans sistemine “eylemsiz referans” deriz. Newton’a göre mutlak uzay ve mutlak zaman göreli değildir. Bunun sebebi Newton’da bir sınırımız vardır. Einstein İzafiyet Teorisinde zaman ve uzayın tek bütün kabul edildiği ve göreceli olduğunu ortaya koymuştur. Sınırları bildiğimiz sürece Newton mantıklıdır.