WHERE WE ARE IN MILKYWAY GALAXY

This is what I've learned so far about where we are in the Milky Way:

1. We are about 26,000 light years from the Galactic Center.

2. We are about 64 light years north of the Galactic Equator (an average based on numerous estimates).

3. The Solar System subtends an angle of only 0.14 degrees from the Galactic Center (tan-1 64/26,000 - less than the portion of the sky occupied by the Sun as seen from Earth - which is about 0.53 degrees).  Illustrations typically greatly exaggerate this angle in their depiction of our sinusoidal path around the Milky Way.

4. We complete one revolution around the Galactic Center once every ~220 million years, with a "vertical period" of about 66 million years (i.e., we pass through the Galactic midplane once every ~33 million years).

5. The sun and planets passed through the Galactic Equator about 2-3 million years ago.

6. Starting with the Earth's North Pole as "up" (or North Celestial Pole), the earth is tilted at 23.4 degrees away from the North Ecliptic Pole, or the sun's axis of rotation.

7. Given this initial frame of reference, the Earth is rotating counterclockwise, and is also revolving counterclockwise in its orbit around the Sun, which is in turn rotating counterclockwise.

8. Starting with the Earth's North Pole as "up," i.e., pointing towards Polaris (the North Star), the Earth is tilted at an angle of 23.4° relative to the Sun's axis of rotation.

9. The Ecliptic Plane, the imaginary disk perpendicular to the Sun's axis of rotation, along which the planets move with relatively small inclinations (except Pluto), is tilted at an angle of about 60.19 degrees above (north of) the Galactic Equator, and is "leaning forward" (although some illustrations show it “leaning back”) in its CLOCKWISE movement around the Milky Way.

10. The orientation of the Earth's axis of rotation relative to the galactic equator is about 27.14 degrees (Galactic Latitude). This is not easy to calculate. You need something called spherical trigonometry to get the answer.

11. The Ecliptic Plane is nearly aligned with the Galactic Center - it's only about 5 degrees away from being bang-on.

It's very difficult to wrap your head around all these different points of view, let alone come up with a decent illustration for all these various perspectives and scales. I'm attaching one that might help.

Orbiter.ch Space News: The ISS crew receives a new tool by email

Orbiter.ch Space News: The ISS crew receives a new tool by email: ISS - International Space Station patch. With a 3D printer, the astronauts on the International Space Station could make some...

Isro lines up 18 missions over the next 15 months | Business Standard News

Isro lines up 18 missions over the next 15 months | Business Standard News

The Soviet Union is first to the Moon

Richard Cavendish explains how, on September 12th, 1959, the Soviet Union launched Luna 2, the first spacecraft to successfully reach the Moon.

Luna 2The space race between the United States and the Soviet Union brought an engaging touch of science fiction to the Cold War. To American astonishment and dismay, the Russians at first took a commanding lead. Their programme was directed by Sergei Korolev, a brilliant aeronautical engineer and expert on rockets, who had displeased Stalin and spent time in the Gulag in the 1930s. He was a commanding figure who did not suffer fools gladly and his staff treated him almost as a god. In the 1950s he developed a massive and at the time almost unthinkably powerful rocket, the R-7, which would propel Soviet spacecraft to the Moon.
Sputnik 1, the first satellite ever launched, created a sensation in 1957 when it hurtled out into space and orbited the Earth every 96 minutes before falling back into the Earth’s atmosphere. Sputnik 2 took the first living creature out into space, a sweet-tempered dog called Laika, though she did not last as long as the Russians pretended. More Sputnik missions tested life-support systems and re-entry procedures. In January 1959 the spacecraft Luna 1 (which Korolev called Mechta, ‘the Dream’) was launched at the Moon, but missed by around 3,700 miles and went into orbit between the Sun and Mars.
Then, on September 12th, 1959 Luna 2 was launched. At just past midnight Moscow time on September 14th it crashed some 240,000 miles away on the Moon not far from the Sea of Tranquillity (perhaps a not entirely appropriate location). Korolev and his people were listening as the signals coming back from the spacecraft suddenly stopped. The total silence meant that Luna had hit its target and there was great jubilation in the control room.
Luna 2 (Luna is Russian for Moon) weighed 390 kilograms. It was spherical in shape with antennae sticking out of it and carried instruments for measuring radiation, magnetic fields and meteorites. It also carried metal pendants which it scattered on the surface on impact, with the hammer and sickle of the USSR on one side and the launch date on the other. It confirmed that the moon had only a tiny radiation field and, so far as could be observed, no radiation belts. The spacecraft had no propulsion system of its own and the third and final stage of its propelling rocket crashed on the moon about half an hour after Luna 2 itself.
The scientific results of Luna 2 were similar to those of Luna 1, but the psychological impact of Luna 2 was profound. The closest any American probe had come to the Moon at that point was 37,000 miles. It seemed clear in the United States that the timing had been heavily influenced by the fact that the Soviet premier, Nikita Khruschev, was due to arrive in the US immediately afterwards, to be welcomed by President Eisenhower. Luna 2’s success enabled him to appear beaming with rumbustious pride. He lectured Americans on the virtues of communism and the immorality of scantily clothed chorus girls. The only way of annoying him seemed to be by refusing to let him into Disneyland.
Korolev had a clincher to come. Only three weeks later, Luna 3 was launched on October 4th, the second anniversary of Sputnik 1, to swing round the far side of the Moon and send back the first fuzzy pictures of its dark side, which no one had seen before. It was an astonishing feat of navigation and it was now possible to draw a tentative map of the Moon’s hidden side.
While the Americans were in disarray, with their space efforts publicly failing (Russian setbacks were kept strictly secret), Korolev went on to put the first man into space, Yuri Gagarin, in 1961. In 1963, on Khruschev’s orders, he propelled the first woman into space, Valentina Tereshkova, which enabled the Soviet Union to make propaganda mileage by claiming that under communism women were treated equally to men.
After 1961, under President Kennedy, American efforts intensified while the Soviet programme suffered from infighting after Korolev’s death at 59 in 1966, following an operation that went wrong. The Luna programme continued and in 1966, the year of Korolev’s death, Luna 9 made the first soft landing on the Moon.
In the end it was of course the Americans who won the race, in 1969, when their astronauts first walked on the Moon. For all the years of rivalry, the viewing room in Russia burst into huge applause as Neil Armstrong took the first steps. The Soviet astronaut Alexei Leonov wrote: ‘Everyone forgot that we were all citizens of different countries on Earth. That moment really united the human race.’

Earth Blog: Hubble Catches a Dusty Spiral in Virgo

Earth Blog: Hubble Catches a Dusty Spiral in Virgo

Luna-Resurs

Luna-Resurs