My Science School

The term Blood Moon once was used in some sects of Christian prophecy to describe a total lunar eclipse that belonged to a tetrad of total lunar eclipses. The most recent Blood Moon – at least by this definition – took place on September 28, 2015. The next one won’t come until April 25, 2032.

The moon orbits around Earth, while Earth orbits around the sun. The moon takes about 27 days to orbit Earth and goes through regular phases in a 29.5-day cycle. The difference in these two cycles has to do with the relative positions of the sun, Earth and moon, which change during the moon's orbit.

Lunar eclipses can only happen during a full moon, when the sun fully illuminates the surface. Usually a full moon has no eclipse because the moon orbits in a slightly different plane than the Earth and the sun do. However, at times the planes coincide. Earth passes in between the moon and the sun and cuts off the sunlight, causing an eclipse.

 

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Baade's Window is an area of the sky with relatively low amounts of interstellar "dust" along the line of sight from the Earth. This area is considered an observational "window" as the normally obscured Galactic Center of the Milky Way is visible in this direction. It is named for astronomer Walter Baade who first recognized its significance. This area corresponds to one of the brightest visible patches of the Milky Way.

Walter Baade observed the stars in this area in the mid-1940s using the 100-inch (2.5 m) Hooker telescope at Mount Wilson Observatory in California while searching for the center of the Milky Way galaxy. Up until this time the structure and location of the galactic center was not known with certainty.

In 2006, the Sagittarius Window Eclipsing Extrasolar Planet Search (SWEEPS) conducted an astronomical survey to monitor 180,000 stars for seven days to detect extrasolar planets via the transit method.

Baade's Window is frequently used to study distant central bulge stars in visible and near-visible wavelengths of light. Important information on the internal geometry of the Milky Way is still being refined by measurements made through this "window". It is in the direction of the constellation of Sagittarius. The window is now known to be slightly "south" of the main central galaxy bulge. The window is irregular in outline and subtends about 1 degree of the sky. It is centered on the globular cluster NGC 6522.

 

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The International Astronomical Union  (IAU) is the only internationally recognized authority for assigning astronomical designations to celestial objects and surface features on them. The purpose of this is to ensure that names assigned are unambiguous. There have been many historical star catalogues, and new star catalogues are set up on a regular basis as new sky surveys are performed. All designations of objects in recent star catalogues start with an "initialism", which is kept globally unique by the IAU. Different star catalogues then have different naming conventions for what goes after the initialism, but modern catalogs tend to follow a set of generic rules for the data formats used.

The International Astronomical Union (IAU) is the officially recognized authority in astronomy for assigning designations to celestial bodies such as stars, planets, and minor planets, including any surface features on them. In response to the need for unambiguous names for astronomical objects, it has created a number of systematic naming systems for objects of various sorts.

 

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Since then, astronomers – who study the universe and everything in it, like planets – have used bigger and better telescopes to find rings around all of the outer gas giant planets: Jupiter, Saturn, Neptune and Uranus. These planets, unlike others in our system, consist largely of gas.

The first theory states that the rings formed at the same time as the planet. Some particles of gas and dust that the planets are made of were too far away from the core of the planet and could not be squashed together by gravity. They remained behind to form the ring system.

The second theory, and my personal favourite, is that the rings were formed when two of the moons of the planet, which had formed at the same time as the planet, somehow got disturbed in their orbits and eventually crashed into each other (an orbit is the circular path that the moon travels on around the planet). 

The other thing that all rings systems share is that they are all made of small particles of ice and rock. The smallest of these particles are no bigger than dust grains, while the largest of the particles are about 20 metres in diameter – about the size of a school hall. All the rings around the planets also contain gaps that are sometimes many kilometres wide and at first nobody could figure out why. We later learned that the gaps were caused by small moons that had gobbled up all the material in that particular part of the ring system.

 

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Tiangong-1 is a single-module space station operated by the China National Space Administration. The module was launched in 2011 and hosted two crews of taikonauts (Chinese astronauts) in 2012 and 2013. Since China's space agency discloses less information about its missions than other space agencies, the details surrounding the space station are not widely known. 

The orbit of the space station passes over most of the civilized world, with the exclusion of northern latitudes that include the United States, Russia and Canada, as well as the extreme south of the world, including Antarctica and the tip of South Africa. However, most of the Earth is covered by water, reducing the chances of a crash in a populated area.

Tiangong-1 (whose name means "Heavenly Palace") weighs about 8.5 metric tons, and is about 34 feet long by 11 feet wide (10.4 meters by 3.4 meters). It contains an experiment module — where the astronauts live and work — and a resource module that contains propellant tanks and rocket engines.

A primary goal for the module was to help the Chinese practice space dockings, which is an important skill for nations looking to build larger space stations or to send multiple spacecraft to the moon, Mars or other locations in the solar system.

 

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The Chang'e 1 lunar orbiter was China's first deep space mission. The program was divided into three phases: circling the Moon, landing on the Moon and returning from the Moon. The program goals were to be accomplished between 2007 and 2020.

The goal of this first mission, besides proving basic technologies and testing out several engineering systems, was to create a 3D map of the lunar surface, to analyze the distribution of certain chemicals on the lunar surface, to survey the thickness of the lunar soil, to estimate helium 3 resources, and to explore the space environment (solar wind, etc.) in near-lunar space.

The Chinese Lunar Exploration Program is designed to be conducted in four phases of incremental technological advancement: The first is simply reaching lunar orbit, a task completed by Chang'e 1 in 2007 and Chang'e 2 in 2010. The second is landing and roving on the Moon, as Chang'e 3 did in 2013 and Chang'e 4 did in 2019. The third is collecting lunar samples from the near-side and sending them to Earth, a task for the future Chang'e 5 and Chang'e 6 missions. The fourth phase consists of development of a robotic research station near the Moon's south pole. The program aims to facilitate a crewed lunar landing in the 2030s and possibly build an outpost near the south pole.

 

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In 2009, NASA launched a spacecraft called Kepler to look for exoplanets. Kepler looked for planets in a wide range of sizes and orbits. And these planets orbited around stars that varied in size and temperature.

Kepler detected exoplanets using something called the transit method. When a planet passes in front of its star, it’s called a transit. As the planet transits in front of the star, it blocks out a little bit of the star's light. That means a star will look a little less bright when the planet passes in front of it.

When a planet passes in front of a star as viewed from Earth, the event is called a “transit”. On Earth, we can observe an occasional Venus or Mercury transit. These events are seen as a small black dot creeping across the Sun—Venus or Mercury blocks sunlight as the planet moves between the Sun and us. Kepler finds planets by looking for tiny dips in the brightness of a star when a planet crosses in front of it—we say the planet transits the star.

Once detected, the planet's orbital size can be calculated from the period (how long it takes the planet to orbit once around the star) and the mass of the star using Kepler's Third Law of planetary motion. The size of the planet is found from the depth of the transit (how much the brightness of the star drops) and the size of the star. From the orbital size and the temperature of the star, the planet's characteristic temperature can be calculated. 

 

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Gamma Cephei Ab is an exoplanet approximately 45 light-years away in the constellation of Cepheus (the King). The planet was confirmed to be in orbit around Gamma Cephei A in 2002, but was first suspected to exist around 1988 (making this planet arguably the first true exoplanet discovered).

The first indications of Gamma Cephei Ab were reported in July 1988. The planet was tentatively identified by a Canadian team of astronomers, which was led by Bruce Campbell, Gordon Walker, and Stephenson Yang, while its existence was also announced by Anthony Lawton and P. Wright in 1989. Though not confirmed, this would have been the first true discovery of an extrasolar planet, and it was hypothesized based on the same radial velocity technique later used successfully by others. However, the claim was retracted in 1992 due to the quality of the data not being good enough to make a solid discovery.

On September 24, 2002, Gamma Cephei Ab was finally confirmed. The team of astronomers (including William D. Cochran, Artie P. Hatzes, et al.) at the Planetary Systems and their Formation Workshop announced the preliminary confirmation of a long-suspected planet Gamma Cephei Ab with a minimum mass of 1.59 MJ (1.59 times that of Jupiter). The parameters were later recalculated when direct detection of the secondary star Gamma Cephei B allowed astronomers to better constrain the properties of the system.

 

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Space shuttles will be replaced quite soon with space planes. America is developing a space plane called Venture Star. It could cost 70% less to fly than the shuttle. Venture Stars could make it possible to reach orbit cheaply, and even to build other ships in space. Then we could make giant transporter ships to carry people to Mars.

Amazing! You might travel to space on a laser beam! Scientists in America are testing a laser that heats a pocket of air under a spacecraft. The very hot air pushes the craft upwards. No energy is wasted lifting heavy fuel off the ground.

Will we ever visit other solar systems?

The nearest star to our Sun is 4.3 light years away. The shuttle would take 158,000 years to get there! We will need amazing new spacecraft before we visit other solar systems.

Will we colonise Mars?

Robots might be able to build a Mars base. Humans would have to wear space suits outside, but would live in airtight habitats, with plants and animals. Genetically modified plants could grow, which would create breathable air and water, making the whole planet habitable.

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America is leading a group of countries to build an international space station (ISS). The space shuttle is used to deliver parts. Most are made in America, but there are Japanese, Russian, Canadian and European parts as well. ISS uses giant solar panels to make its own Electricity.

Amazing! John Glenn went to space at the age of 77. Sensors on his skin were used to monitor his health. His record-breaking flight happened 36 years after his first space trip, when he was the first American to orbit the Earth.

Will there ever be a Moon Base?

If space gets a lot busier it will make sense to use the Moon as a base. The Moon’s low gravity lets big spacecraft take off and land easily compared to Earth.

Is it true? People can be ‘buried’ in space.

Yes. A cheap new rocket called Pegasus has made space funerals possible. The rocket delivered 25 people’s ashes into space in 1997. For under $3,000 each, the ashes were scattered in orbit. They will drift back to Earth after a few years.

Will I ever go to space?

Only a few people become astronauts. But tourists may soon be able to holiday in space. There are plans to use empty shuttle fuel tanks as the rooms of space hotel!

The Mars Pathfinder probe dropped on to Mars inside a bundle of balloons. The balloons bounced away from the falling parachute, deflated, and then the Sojourner rover slowly drove away over them.

Who drove a vehicle on Mars?

The Mars Pathfinder (1997) had a small, six-wheeled rover, called Sojourner. It used a camera and laser beams to find its way. Scientists on Earth asked Sojourner to examine particular objects, by radio. But the robot car had to decide how to reach them.

Is it true? There is life on Mars.

No. probes have tested Martian soil for life. They added food to the soil to see if there was anything living there that was hungry! There wasn’t. Then scientists found what looked like fossils inside a rock from Mars. After careful checking, they decided that the shapes were probably odd looking crystals. So there is no life on Mars, unless it is very good at hiding from us!

Amazing! For 20 years before Pathfinder, several probes sent to Mars ended in disaster. Sixteen probes from Russia either exploded on launch, missed the planet, or crashed into its surface. The American probe Observer exploded as it entered Mars’s orbit. Some probes just went missing. Nobody knows why.

Did Vikings really land on Mars?

Two space probes, called Viking 1 and Viking 2, landed on Mars in the 1970s. They took 3,000 photos, some in 3-D, and beamed them back to Earth. The Viking probes also measured weather patterns and examined the soil for signs of life. They didn’t find any aliens.

Humans can’t travel to other planets yet. A trip to Mars would need much bigger spacecraft than the shuttle. Instead, unmanned space probes like Voyager can travel through the solar system, sending home pictures of the planets.

Is it true? A Mariner took photos of Mercury.

Yes. A very successful space probe called Mariner 10 visited the planet Mercury three times in the 1970s. As well as taking photos, Mariner discovered Mercury’s strange magnetic field, and signs of ice at the poles.

Which probe got too hot?

Four Venera probes have landed on Venus. The temperature there is a sweaty 480o C. As if that wasn’t nasty enough, the clouds rain pure sulphuric acid!

Amazing! The Huygens probe will parachute on to Saturn’s largest moon in 2004. Huygens is hitching there on a Saturn probe, Cassini. Titan is bigger than the planets Mercury or Pluto. Titan has its own, cloudy atmosphere, blocking our view of its surface. Titan might be covered in an ocean, so Huygens is designed to float!

Which probe visited a comet?

Giotto was made to visit Halley’s Comet as it passed Earth in 1986. Giotto had a special shield to protect it from the dust of the comet’s tail. The probe took measurements and photographs from 600 km away, revealing the rocky heart of the comet.

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Astronomers on Earth have their view spoilt by our cloudy, dirty atmosphere, which makes stars seem to twinkle. There is no air in space, so distant objects are much clearer. The Hubble Space Telescope has taken photos of galaxies 13 billion light years away!

Amazing! You can join space telescopes together to make one huge eye in the sky! First, lots of small space telescopes have to be launched into space. Then they need to line up, like beads on a very big necklace. Computers compare what each telescope can see, and fill in the gaps. This can make a virtual telescope as big as a city!

Is it true? The Hubble telescope can see stars being born.

Yes. The Hubble image here shows stars being made in the Eagle Nebula. The fingers of cloud are bigger than our entire solar system. They are made of gas and dust, which slowly collects into lumps. As they grow, the lumps become hotter, creating thousands of new stars!

What happens if the telescope breaks down?

Hubble had to be fixed by astronauts almost as soon as it was launched. The mirror it uses to collect images was the wrong shape, making pictures fuzzy. In December 1993 a shuttle met up with Hubble, and astronauts adjusted the mirror successfully.

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Anything in orbit around the world is a satellite. Man-made satellites are normally smaller than a car. People make satellites for special jobs. Some study the Earth, some bounce electronic messages around the world, and some are telescopes for studying the universe. Earth has a natural satellite, too - the Moon.

How do satellites stay up?

Once satellites have been launched by rocket, they try to zoom off into space, while the Earth tries to pull them down. The two movements added together balance out, making the satellite travel in a circle, called the orbital path.

Is it true? There are spy satellites in the sky.

Yes. A big reason for the space race between Russia and America was to spy on each other. Spy satellites use telescopic cameras. Earth spy satellites used to drop films to Earth by parachute. Now they take digital photos and beam them home, using secret codes.

Do satellites ever fall out of the sky?

Yes, accidents can happen! Satellites have crashed into the ocean, and pieces of the empty space station, Skylab, were found on farmland in Australia, after it fell back to Earth in 1979.

Amazing! There are 150,000 bits of space garbage! They fly at incredible speeds, making them very dangerous. A window on a space shuttle was chipped once by a collision with a flake of paint! The American air force keeps track of the largest 8,500 objects in orbit. Letting rubbish drop and burn-up in the atmosphere helps to clean up space.

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American Saturn 5 rockets were 111-metre tall monsters, weighing 2,903 tonnes on the launch pad. That’s as heavy as 600 elephants! They were more greedy than elephants, too, burning 15 tonnes of fuel per second. Saturn 5 rockets were used to launch all the Apollo missions to the Moon.

What do rockets carry?

Rocket cargo is called the payload, the load that pays for the trip. Most rockets are designed to carry one or two satellites. Some satellites are for scientific research, some are for communication, and some are for spying. Of course, rockets can also carry people!

Is it true? Jet planes can fly in space.

No. jet engines need to take oxygen from the air around them to burn fuel. Because, there’s no air in space, a jet engine wouldn’t work up there.

Why do rockets have stages?

Rockets have to be big to carry enough fuel to escape the Earth’s pull. But once the fuel is burnt, those big engines and fuel tanks are useless. Their weight would make visiting the Moon very difficult. So rockets are made in stages, or pieces, which drop off when they’ve done their job.

Amazing! Three German engineers made a rocket-powered car in 1928! Fritz von Opel, Max Valier and Friedrich Sander tested the first version, Opel-Rak 1, on March 15, 1928. Opel later used the rocket knowledge he learnt from Valier to fit 16 rockets on to a glider plane. It was the second ever rocket-powered aircraft.