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Science Challenge 2014 > Space science set 2 > Flashcards

Space science set 2 Flashcards

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1
Q

What is radio astronomy?

A

Radio astronomy is a sub-field of astronomy that studies space (celestial objects) using radio frequencies

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2
Q

Instead of using visible light, what does radio astronomy measure?

A

Radio astronomy measures the radio waves of celestial objects.

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3
Q

How were radio waves discovered?

A

Radio waves were discovered by accident by Karl Jansky in 1931.

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4
Q

What was Karl Jansky doing that he happened upon radio waves?

A

Jansky was trying to figure out the static noise that was interfering with radio telephone services.

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5
Q

What did Jansky discover?

A

Jansky discovered a sound that reoccurred every 23 hours and 56 minutes.

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6
Q

Why was the timing of the sound important?

A

The time of 23 hours and 56 minutes is the time it takes for the earth to rotate

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7
Q

What is a sidereal day?

A

The sidereal day is the time it takes for an object to come back to the same location after one rotation of the earth

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8
Q

What realization did Jansky come to because of the strange timing?

A

He realized that the sound was not from earth.

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9
Q

where was the sound coming from?

A

The sound was coming from the Milky Way, around Sagittarius constallation.

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10
Q

What is an astronomical map?

A

An astronomical map is a map of the star systems… where celestial objects are in the sky

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11
Q

What did Grote Reber do?

A

Grote Reber built the first dish-shaped radio telescope in his back yard in 1937

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12
Q

Why do radio telescopes need to come in different shapes and sizes?

A

Radio telescopes need to be in different shapes and sizes because radio waves range from 3m to 30 m

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13
Q

How has technology improved radio telescopes?

A

Technology has meant that the telescopes can be networked together to act as one huge telescope

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14
Q

What is interferometry?

A

Interferometry is when they network (join with wires and computers) a bunch of radio telescopes so they act like one giant dish

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15
Q

Where is the VLA Very Large Aray?

A

The VLA is in New Mexico, and it has 27 25 m diameter radio antennas set in a y formation

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16
Q

How does a radio telescope work?

A

the dish is a concave shaped (parabolic) reflector that takes the incoming radio waves and brings them into focus (like a mirror reflecting telescope)

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17
Q

What shape is a radio telescope?

A

A radio telescope is concave

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18
Q

What is the Cassegrain design?

A

Cassegrain design uses a secondary reflector (like a 2nd mirror) and a feed horn to bring the radio waves into sharp focus.

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19
Q

What is at the feed horn?

A

An antenna is at the feed horn

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20
Q

What does the antenna do?

A

An antenna converts the radio waves into an electric current

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21
Q

How do they stop random interference from affecting the current?

A

They cool the telescope with liquid nitrogen or liquid helium to stop any random signals.

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22
Q

What are random signals called?

A

Noise

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23
Q

Why do they want less noise?

A

The clearer the signal, the less noise there is, the easier it is to pick up very weak signals from space

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24
Q

What does the tuner do?

A

The tuner allows the astronomer to focus in on a single radio signal from the thousands that come into the antenna

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25
Q

What is an amplifier?

A

An amplifier increases the strength of the weak electrical current caused by the radio signals

26
Q

Why do they need it to be hooked up to a computer?

A

The computer System records and stores all the electric signals, helps them analyze data and controls the telescope’s movement

27
Q

What is SETI?

A

SETI is the Search for Extraterrestrial Intelligence (Aliens)

28
Q

What are people in SETI doing?

A

SETI scientists are looking for life in other places in the universe.

29
Q

How do they think they might find life on other planets?

A

They think that other planets might be sending out electrical signals as well

30
Q

How might they tell if it is a life form’s signal?

A

They think that a signal from other life forms would be artificially produced and could be separated from the universe’s background noise.

31
Q

How is human made radio different than nature’s radio?

A

Human radio waves are in a narrow band, ie they are in a narrow band of the electromagnetic spectrum – like tuning into a radio staion

32
Q

what might an alien signal do?

A

They think an alien signal will be repeated, so they search the narrow bands looking for repeating sounds

33
Q

What will a repeated signal show?

A

A repeating signal will prove there is life in other places

34
Q

When did we send a message to space?

A

In 1974, November we sent a message to space.

35
Q

To what location in space did we send the message?

A

We sent the message to the M12 star cluster, 21 000 light years away

36
Q

Where was the space message sent from

A

The space message was sent from the Arecibo radio telescope in Puerto Rico

37
Q

What was the space message we sent?

A

The message was 1679 binary numbers ( 0s and 1s), if organized into a 23 column by 73 row run-length coding image told them information about us, our DNA, a human picture, a solar system map, and a picture of a telescope that sent the image

38
Q

When should we expect a response if they got it on M12?

A

It will take 42 000 years to get the reply

39
Q

Where on the electromagnetic spectrum would a smart alien send a signal?

A

On the 1-10 Ghz level there is little noise, so this would be the best channel

40
Q

Where are SETI building their own radio telecope?

A

At the SETI institute at the University of Berkeley in California they are building their own alien finding telescope

41
Q

Who was the first person to think he heard some alien noise?

A

In 1899 Nikola Tesla heard some unexplained signals on his Tesla coil. He thought it was from Mars.

42
Q

What did Marconi and Kelvin believe?

A

Marconi and Kelvin both believed we could use radio signals to communicate with beings on Mars.

43
Q

What weird thing happened in 1924?

A

In 1924 Mars passed very close to earth so for 5 minutes every hour they had radio silence and listened for signals from Mars.

44
Q

Who was there to decipher messages?

A

Cryptographers were they at the ready to decipher messages from Mars

45
Q

Why do SETI researchers dream of that time?

A

Nowadays they have to filter out so much human radio noise, it is very difficult

46
Q

When did modern SETI begin?

A

Modern SETI began in 1960 with Project Ozma

47
Q

Who was project Ozma named after?

A

The wizard of Oz was the namesake for project ozma

48
Q

What did Frank Drake do with his Project Ozma?

A

He pointed two radio telescopes at two nearby stars for four months at 1.4 Ghz looking for signals from aliens. This inspired government to fund research like this

49
Q

How can you participate in SETI?

A

Go to SETI@Home and they can use your computer to help them search the data from the radio signals from space!!

50
Q

What do microwave telescopes do?

A

Microwave telescopes give insight into the radiation field that is around the universe

51
Q

What is the Big Bang?

A

The Big Bang is what scientists think started the universe.

52
Q

What are infrared telescopes good at doing?

A

Infrared telescopes peer through the dust of the universe that blocks visible light.

53
Q

What do ultraviolet telescopes do?

A

Ultraviolet telescopes can see into the chemical composition of the galaxy and helps to see changes over time.

54
Q

Although our atmosphere protects us from harmful rays, how does it hinder astronomers?

A

Our atmosphere can absorb some wavelengths of light and distort images.

55
Q

What is the Hubble Space Telescope?

A

The Hubble Space Telescope was launched into space to get past the atmosphere and has been peering into space for over 20 years.

56
Q

What does the Chandra X-Ray telescope observe?

A

The Chandra X-ray telescope measure xrays from space!

57
Q

What will be launched into space in 2018?

A

In 2018 the James Webb space telescope will be launched into space to work outside the atmosphere

58
Q

What is the Kuiper Airborne Observatory and the SOFIA Stratospheric Observatory for Infrared Astronomy?

A

They are both observatories that are built onto aircraft, and take measurements 12 km up into the sky where there is less water vapor.

59
Q

What does water vapour absorb?

A

water vapour absorbs infrared radiation

60
Q

What are strata-scopes and BLASTs

A

They are telescopes on high altitude balloons (1950s to 1970s) BLASTS are Balloon-borne Large Aperture Sub-millimeter Telescopes (2005-2010)

61
Q

What is the largest telescope to leave the ground to date?

A

The Sunrise telescope looks at our sun.It goes in the arctic summer and goes up on balloons.

62
Q

What is the purpose of all telescopes?

A

All telescopes tell us more about our universe.

Science Challenge 2014 (24 decks)

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