Jupiter: King of Planets

Jupiter is the fifth planet from the Sun and the largest in the Solar System,  Jupiter is named after the Roman god of sky and thunder in fact Jupiter was the “King of the Gods” the equivalent of the Greek God Zeus.  Jupiter is the fourth brightest object in our solar system is visible to the naked eye and was first recorded by the ancient Babylonians in around the 7th or 8th century’s BC.  It couldn’t be more accurately named because Jupiter is massive, I mean really massive.  In fact if Jupiter got any more massive, it would actually shrink due to the gravitational effects causing it to pull in on itself. Jupiter mass is incredibly two and a half times that of the combined mass of all other planets in the entire solar system.  Jupiter is almost like its own mini solar system.  It has four main large moons, Io, Europa, Ganymede, and Callisto, however Jupiter has 67 confirmed moons which are in turn split into three categories, Inner, Galilean and Outer.  It even has a faint ring system around it.  I will come back to these moons and ring system at another time to discuss in more detail.

A Jovian day takes just under 10 Earth Hours making it the fastest rotating body in our Solar System. However it will take 12 Earth Years for Jupiter to complete one orbit around the sun! This means Jupiter has only made two complete revaluations of the sun in my lifetime!  Jupiter is more than five times farther than the sun than Earth. That’s 484 million miles (778 million kilometres) or 5.2 Astronomical Units.  However its presence is felt throughout the solar system acting like a cosmic shield that eats up or sling shots away any would be comets or asteroid’s that would collide with earth.  Jupiter’s gravity of is only  2 and a half times what it is on Earth, due to it being made up of gases.  Jupiter is the first of the gas giants that live in the outer solar system composed 89.8 percent molecular hydrogen, 10.2 percent helium, minor amounts of methane, ammonia and water.  Unlike the planets Mercury, Venus Earth and Mars it does not have a solid core the gaseous material it is made from simply gets denser with depth. The colourful cloud belts of Jupiter are arranged in dark and light zones created by strong east-west winds in the planet’s upper atmosphere which are made of ammonia crystals and sulphur traveling at speeds more than 400 miles an hour (640 kilometres per hour).   The huge “Red Spot” that appears in the cloud belt is an enormous storm that has been raging for over 300 years. This storm is big that three Earth’s would fit inside of it.

There have been a lot of missions to Jupiter beginning with NASA’s Pioneer 10 spacecraft in December 1973 followed by then Pioneer 11 in December 1974. Voyager 1 and 2 in 1979 where the last until Ulysses arrived in February 1992. Cassini made a flyby in 2000, on its way to Saturn. And finally, NASA’s New Horizons spacecraft made its flyby in 2007.   Below are a few links to the sites I gathered my information on but I would like to advise you to check out www.astronomycast.com and www.universetoday.com Photo Credit:  Reto Stöckli, Nazmi El Saleous, and Marit Jentoft-Nilsen, NASA GSFC.

Thanks To: theplanets.orgsolarsystem.nasa.gov, science.nationalgeographic.com,  universetoday.com,  space-facts.com,  astronomycast.com,  astronomyonline.org,  planetfacts.org

Advertisements

The Asteroid Belt: A Hundred Million Miles of Rock

The asteroid belt is the region of the Solar System located in between the orbits of the planets Mars and Jupiter and marks the gateway to the outer solar system.  The Asteroid belt takes up a massive region of that space, roughly two and half times the distance from the Earth to the Sun.  It is a vast collection of rocks and ice left over from the formation of the Solar system however despite popular imagery the asteroid belt is mostly empty.  Yes there are billions possibly trillions  of asteroids in the belt but they are so small and spread over such a vast area that if you were to stand on one asteroid it would be extremely unlikely to see its neighbour.  The Asteroid belt contains relatively small sized asteroids, ranging from the size of boulders to a few thousand feet in diameter however there are a few inhabitants that are considerably larger.

Ceres: Ceres was discovered in on New Years day in 1801 by Giuseppe Piazzi and was named after the goddess of agriculture, grain crops, fertility and motherly relationships. Ceres for a time referred to as a planet until 1851 when its asteroid term became more well established. In 2006 Cerces was again reclassified as a Dwarf Planet alongside Pluto and is today the is the closest dwarf planet to the sun.

Vesta: Vesta was discovered by the German astronomer Heinrich Wilhelm Olbers on 29 March 1807 and was named for the  virgin goddess of home and hearth from Roman mythology. Vesta is the brightest asteroid in the Solar System and can been seen with the naked eye.

Ganymed: Ganymed is a large asteroid that should not be confused with Jupiters moon  “Ganymede”.  Ganymed was discovered October 23, 1924  by Walter Baade. Ganymed has a very well maped out orbit and its next close fly by of Earth will be on 13 October 2024 when the asteroid will only be 35(ish) million miles away.

Eros: Eros was discovered on the 13 August 1898 by Gustav Witt  and Auguste Charloisis and was named after the Greek god of love “Erōs”.  Eros is the first asteroid to be landed upon by a spacecraft, the Near Earth Asteroid Rendezvous (NEAR) mission, which landed on the asteroid in 2000.

The asteroid belt is full of many fascinating andl interesting pockets of information however with such a vast amount of different asteroids, comets and proto-planets I will need to revisit this region of our solar system at another time in the future.  Below are a few links to the sites I gathered my information on but I would like to advise you to check out www.astronomycast.com and www.universetoday.com and  earthsky.org

Thanks To: theplanets.orgsolarsystem.nasa.gov, science.nationalgeographic.com,  universetoday.com,  space-facts.com,  astronomycast.com,  astronomyonline.org,  planetfacts.org earthsky.org

Phobos and Deimos: Chariots of Fear and Terror

The moons of Mars Phobos and Deimos are suitably named as they refer to the mycological characters Phobos (panic/fear) and Deimos (terror/dread) who accompanied the god of war Ares into battle. Ares as you may remember is what the ancient Greeks called Mars.  Deimos was discovered 138 years ago on this very day (12 August) by the American astronomer Asaph Hall.  Phobos was also discovered by Hall six days after that (18 August). The Martian moons are among the smallest in our solar system.

Phobos is slightly larger than his brother but still rather small at only about 17 miles long (27km) at its greatest diameter. Its surface is covered in craters the largest being a 6 miles wide.  The impact that created this crater not only almost destroyed Phobos but also caused extraordinary streak patterns across the moon’s surface.  It hurtles around Mars three times a day ,orbiting only 3,700 miles (6,000 km) above the Martian surface and is gradually getting closer.  It is spiralling inward at about 2 meters each century meaning that sometime within the next 50 million years, it will either crash into Mars or be destroyed but tidal gravitational forces and form a ring around the planet.

Deimos orbits at a much further distance than his brother at around 14,573 miles (23,460 km) and also has a much longer orbital period of about 30 hours. Deimos is just a little over 9 miles long (15 km) making it one of the smallest moons in the entire solar system. Its surface has much less detail due to the thick layer of dust.  Deimos is slowly moving farther away from Mars, just like our own moon is slowing moving away from earth.  Eventually it will break free of the gravitational pull of Mars and will leave orbit, never to be see again.

The two Martian moons have been a lot more interesting than I had first belived them to be, Mars has been in the spotlight a lot in recent years and it is easy to forget about its two be it small companions.  Below are a few links to the sites I gathered my information on but I would like to advise you to check out www.astronomycast.com and www.universetoday.com Photo Credit:  Reto Stöckli, Nazmi El Saleous, and Marit Jentoft-Nilsen, NASA GSFC.

Thanks To: theplanets.orgsolarsystem.nasa.gov, science.nationalgeographic.com,  universetoday.com,  space-facts.com,  astronomycast.com,  astronomyonline.org,  planetfacts.org

Mars: The Next Giant Leap for Mankind

Mars is the fourth planet from the Sun and the last of the terrestrial planets. Mars is named after the Roman god of war, known to the ancient Greeks as Ares, ancient Chinese as fire star while ancient Egyptians names it “Her Desher” which roughly translates means “the red one”. The month of March also derives its name from Mars and it is often described as the “Red Planet” due to its reddish appearance.  Mars is a small planet, second smallest after Mercury but has managed to capture two moons Phobos and Deimos which I will discuss in greater detail later!  A Martian day takes just a longer than an Earth Day lasting about 24 and a half hours while the Martian year will take 687 Earth days. This means if I where a Martian id only be 17 years old!  Gravity is a lot less on Mars too, Martian surface gravity is only 37% of the Earth’s meaning I would weigh about 4 and a half stone and could leap nearly three times higher than I could on earth!

Mars is a terrestrial planet with a thin atmosphere composed primarily of carbon dioxide (95%) with nitrogen (2.7%), and argon (1.6%), with traces of oxygen and water.  Its surface is where the real interesting things happen!  Mars is home to the tallest mountain known in our solar system.  Olympus Mons is a 16 miles (25 km) high and 374 miles (624) wide, now dormant volcano located on the western hemisphere.  To put this into perspective Olympus Mons is three times taller than Mount Everest and if places on earth would take up most of Germany.  Valles Marineris at more than 2,500 miles (4,000 km) long, 120 miles (200) wide and up to  4 and a half (7 km) deep making it  one of the larger canyons of the Solar System.  If places on earth it would look like the grand canyon if it stretched from New York to San Francisco. Mars is the only other terrestrial planet in our solar system to have polar ice caps. The northern cap is called the Planum Boreum, with Planum Australe in the south. The Martian polar ice caps have two kinds of ice. firstly water ice, like the our own ice caps on Earth and dry ice of frozen  carbon dioxide.

We have sent an army of robotic explorers to mars over the past 45 years but only 16 of the 39 missions have been success. Beginning with the USSR’s Marsnik 1 which was launched in 1960, 39 orbiters, landers and rovers have been to Mars.  At the moment the two Mars rovers  Curiosity and Opportunity are roaming about the surface sending back some amazing photos and looking for signs of ancient life.  In 2016, Europe’s Exobiology on Mars program  be launched to investigate Mars and any signs of current potential life.  Consisting of two separate missions an orbiter and lander set for 2016 launch and and a European rover and a Russian surface platform launching in 2018.  Below are a few links to the sites I gathered my information on but I would like to advise you to check out www.astronomycast.com and www.universetoday.com Photo Credit:  Reto Stöckli, Nazmi El Saleous, and Marit Jentoft-Nilsen, NASA GSFC.

Thanks To: theplanets.orgsolarsystem.nasa.gov, science.nationalgeographic.com,  universetoday.com,  space-facts.com,  astronomycast.com,  astronomyonline.org,  planetfacts.org

The Moon: Full Moon Names

Cultures across the globe have given names to the full moon throughout the year. Different full moon names can be found among the Chinese, Celtic, Old English, Native American  and New Guinea cultures, to name a few.  The full moon names were used to identify the entire month during which each occurred often referring to hunting and or farming conditions.  The names given below are some of the most common however each culture has specific variations so look them up if you find it as interesting as I do!

Full Moon Names

Wolf Moon – January.
Snow Moon – February
Worm Moon – March
Pink Moon – April
Flower Moon – May
Strawberry Moon – June
Buck Moon – July
Sturgeon Moon – August
Harvest Moon – September
Hunter’s Moon – October
Beaver Moon – November
Cold Moon – December

Due to the 29 and a half day lunar cycle the exact dates of the full moons move every year. Most seasons will have three full moons, but because of the variation some will actually have four. The term “Blue Moon” was used to identify one of these extra full moons. July’s “Buck moon” will appear in the sky later tonight .  Below are a few links to the sites I gathered my information on but I would like to advise you to check out www.astronomycast.com and www.universetoday.com and  earthsky.org

Thanks To: theplanets.orgsolarsystem.nasa.gov, science.nationalgeographic.com,  universetoday.com,  space-facts.com,  astronomycast.com,  astronomyonline.org,  planetfacts.org earthsky.org

The Moon: Lunar Calendar

The time between successive new moon phases is 29 and a half Earth days. The moons phases where briefly described in my last post in Astronomy called  Our Astronomical Companion however as I found it so fascinating I wanted to go a little deeper into it and explain in detail the phases it goes through.  One major misconception is that the phases of the moon are linked to the earth’s shadow, however the only time earth’s shadow comes into play is during eclipses of the moon which occur every six months. In fact it’s the moons own shadow which accounts for its phases.

Moon Phases 

New Moon:  The moon rises and sets with the sun whose light is shining directly behind the moon and so the side that faces earth is covered in its own shadow and is not visible. A New Moon is a one day event and occurs at a very specific time which can be measured down to the second. The nights sky is considerably darker at this stage.

Waxing Crescent:  The first Phase after the New Moon The moon has moved in its orbit and so a slim crescent is visible in the west after sunset which over the next seven days or so will become increasingly brighter or  “Wax”  in illumination.

First Quarter:  Commonly called a “Half Moon” is when the moon is one quarter of the way around in its orbit of Earth and is a one day event which occurs roughly 7 days after the New moon.  A Quarter Moon also named as we see 1/4 of the illuminated surface.

Waxing Gibbous:  The moon appears high in the east at sunset and is more than half-lighted, but less than full.  This phase lasts roughly seven days with the moon continuing to “Wax” until its peek at the next stage.  The word “Gibbous” has it’s roots in the Latin word “gibbosus” meaning humpbacked.

Full Moon:  We can see the entire illuminated portion of the moon. At this point the Moon and Sun are on a line, with Earth in between. This is the opposite in many ways of the New moon which is totally covered in its own shadow and its timing can be measured to the second. Each new full Moon has its own name which i will talk about in a later post.

Waning Gibbous:  The first phase after a Full Moon occurs  finds the moon in an ever decreasing state of illumination or “Waning” It lasts roughly 7 days and is visible over the eastern horizon in the hours between sunset and midnight. This phase is the one that looks most like the Death Star from Star Wars to me!

Third Quarter:  Also referred to as “Last Quarter” is another “Half Moon”, but the illuminated part is opposite of the First Quarter.   A Third Quarter moon is a one day event when the moon is three quarter of the way through it’s orbit around the earth.  It rises around midnight, appears at its highest in the sky at dawn, and sets around noon.

Waning Crescent:  Sometimes refereed to as an “Old Moon” is best viewed an hour or two before the sunrise in the east before dawn. This last phase begins after the Third Quarter and will last around seven days until the  cycle begins again with a New Moon.

Todays or be it tonight’s moon phase is a Waxing Crescent with 32% Illumination.  The skys will hopefully stay clear enough for you to see the Moon in the wester sky after sunset. The Moon holds so many more fascinating topics for discussion so I will be returning  to it again soon! Below are a few links to the sites I gathered my information on but I would like to advise you to check out www.astronomycast.com  www.universetoday.com  and moongiant.com.

Thanks To: theplanets.orgsolarsystem.nasa.gov, science.nationalgeographic.com,  universetoday.com,  space-facts.com,  astronomycast.com,  astronomyonline.org,  planetfacts.org earthsky.org

The Moon: Our Astronomical Companion

The moon called Luna by the Romans, Selene and Artemis by the Greeks, and many other names in other mythologies, is Earth’s only natural satellite, our closest astronomical companion and it is the second brightest object in the sky after the Sun.  The moon has been a source of inspiration from 10th-century Japanese folktales to modern day science fiction.

The amount of time the Moon takes to complete one turn on its axis with respect to the stars is 27.3 days, and it’s called a sidereal day.  This corresponds with the Moons orbital period of the Earth which also takes just over 27 days meaning that the Earth and the moon are tidaly locked.  The time between successive new moon phases is 29 and a half Earth days. The moons phases are easy to describe. Basically half of the moon is always illuminated by the sun, what changes is the position of the moon itself and what aspects of it we are able to see from earth. The moon begins as a New Moon which is covered in shadow and not visible. In its orbit the Moon will gradually become increasingly brighter, referred to as “Waxing”, until it becomes a Full Moon.  After a Full Moon the Moon will gradually become darker, referred to as “Waning” as it makes its journey back into a New Moon where the cycle begins again.  This is actually very fascinating and I will talk about it in greater detail in another post.

The Moons atmosphere is extremely thin. This means that the surface of the Moon is unprotected from cosmic rays, meteorites and solar winds, and has huge temperature variations. The lack of atmosphere means no sound can be heard on the Moon, and the sky always appears black.  In fact due to this extreme heat and ultraviolet conditions on the moon the flags that have been left there 40 plus years ago have most likely been destroyed, and if they are still intact they would be bleached white. The surface of the moon is covered in dust with the same consistency as talcum powder.  The Moon has much weaker gravity than Earth, due to its smaller mass, so you would weigh about one sixth (16.5%) of your weight on Earth, making me about 2 stone or so!   Dark side of the moon is a myth! I’m talking about the misconception that one side of the Moon is always shrouded in darkness, not the Pink Floyd album.  While one side of the mood is all we can see the other side or far side of the Moon does see the sun’s rays. The rise and fall of the tides on Earth is caused by the the gravitational forces that the Moon exerts.  The moons Gravity causes bulges to move around the oceans as the Earth rotates, causing high and low tides around the globe.

The Moon was first visited by the Soviet spacecraft Luna 2 in 1959. It is the only extraterrestrial body to have been visited by humans. The first landing was on July 20, 1969  with Neil Armstrong on the Apollo 11 mission being the first man to step foot on its surface.  The last was in December 1972 with Gene Cernan on the Apollo 17 mission, since then the Moon has only be visited by unmanned vehicles.  The Moon is also the only body from which samples have been returned to Earth. In the summer of 1994, the Moon was very extensively mapped by the little spacecraft Clementine and again in 1999 by Lunar Prospector.

The Moon has always been a muse for me, its silver light cold hauntingly beautiful and mysterious, it is one of the reasons I am fascinated in astronomy.  I will be returning to the Moon in many other posts because there is just is so many fascinating subjects to cover!  Below are a few links to the sites I gathered my information on but I would like to advise you to check out www.astronomycast.com and www.universetoday.com and  earthsky.org. Photo Credit:  

Thanks To: theplanets.orgsolarsystem.nasa.gov, science.nationalgeographic.com,  universetoday.com,  space-facts.com,  astronomycast.com,  astronomyonline.org,  planetfacts.org earthsky.org