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Forums - General - Scientific question(s)

hatmoza on 25 September 2009
mrstickball said:
Hi, here are some answers I hope will help you:

1) The reason for this should be under the same reason we do not see stars during the day, regularly. Stars and to a lesser extent, the moon do not have a high enough magnitude to overcome the brightness of the sun. When the moon is full or new, it projects the highest amount of sunlight possible to the earth, and usually does break through to where you can see it in the day time in some cases. Also, the tilt of the earth does not always equate to the tilt of the moon, which further constrains the issue of seeing the moon regularly. However, in some rare cases, even, we can see other planets during the daytime. Venus and Mars are sometimes seen when they reach close proximity to the earth.


I don't think you can compare the moon to stars as the the moon doesn't emit its own light but reflects the suns light. Thats why we can still see it during the day. Stars on the other hand are WAAAY further away than both the moon and sun and thats when your explanation comes into play.



I am the black sheep     "of course I'm crazy, but that doesn't mean I'm wrong."-Robert Anton Wilson

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Orca_Azure on 25 September 2009
hatmoza said:
dtewi said:

Well, they're technically astronomy, but whatever.

1) If the moon is constantly orbiting the Earth, why is it that we only see it regularly during nighttime?

2) If there were a planet oribiting the sun and was equidistant from the sun as Earth, how would we know if that planet existed?

Very random questions out of the blue. Just want a couple answers that don't include highly-confusing science mumbo-jumbo.


You can still see it in the day, It's just not that bright because the suns light is too powerful. At night we see the moon because it's reflectling the sun's light and that's why we only see parts of the moon  because only part of the moon is facing the sun. But it's not always possitioned opposite of where you live on earth. According to the lunar calender you see it 15 days of every 30 days 30 out of every 60 days(ie on  one half side of the earth's orbit).

I don't get the second question.

What hatmoza said

2- we'd know it because we have technology to scan the space near us. Telescopes and orbitting satellites would eventually tell us about a sister planet



mrstickball on 25 September 2009
hatmoza said:
mrstickball said:
Hi, here are some answers I hope will help you:

1) The reason for this should be under the same reason we do not see stars during the day, regularly. Stars and to a lesser extent, the moon do not have a high enough magnitude to overcome the brightness of the sun. When the moon is full or new, it projects the highest amount of sunlight possible to the earth, and usually does break through to where you can see it in the day time in some cases. Also, the tilt of the earth does not always equate to the tilt of the moon, which further constrains the issue of seeing the moon regularly. However, in some rare cases, even, we can see other planets during the daytime. Venus and Mars are sometimes seen when they reach close proximity to the earth.


I don't think you can compare the moon to stars as the the moon doesn't omit its own light but reflects the suns light. Thats why we can still see it during the day. Stars on the other hand are WAAAY further away than both the moon and sun and thats when your explanation comes into play.

Actually, it doesn't matter.

The key is the apparent magnitude provided to the earth. The sun's typical magnitude is rated at -26.7, while a full moon is rated at -12.3. This equates to the sun being 449,000 times brighter than the moon is to us. The brightest planets in the sky rates up to -4.6 which would be Venus.

The absolute minimum magnitude for an object to be viewed during the daytime is -4.0. The brightest star (Sirius) is rated at -1.46 which is much lower than the threshold.

 Here's a scale:

http://en.wikipedia.org/wiki/Apparent_magnitude

Hopefully this explains it a little bit better.



Back from the dead, I'm afraid.

avinash habashi on 25 September 2009

i have a question

how did the moon get to where it is?



ManusJustus on 25 September 2009
dtewi said:

1) If the moon is constantly orbiting the Earth, why is it that we only see it regularly during nighttime?

2) If there were a planet oribiting the sun and was equidistant from the sun as Earth, how would we know if that planet existed?

1) You can see the moon as much in the day as you can at night.  You may not notice it as much during the day because it is reflects less light and everything else is much brighter, but it spends as much time in the day sky and it does in the night sky.

2) We could spot this planet in the same way that we spot every other planet.  However, another planet in Earth's orbit could not exist, physics has a tendency to concentrate masses in the same orbit and if it was possible for such a phenomenom to form, it would have to have the same exact mass and speed as Earth to stay in the same orbit without colliding.



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dtewi on 25 September 2009

Why is everyone still saying the SAME thing?

Honestly, let this thread die.



Kimi wa ne tashika ni ano toki watashi no soba ni ita

Itsudatte itsudatte itsudatte

Sugu yoko de waratteita

Nakushitemo torimodosu kimi wo

I will never leave you

Rath on 25 September 2009
avinash habashi said:
i have a question

how did the moon get to where it is?

Most likely something big hit the earth and the stuff that came from the collision formed the moon.

 

As for the planet on the other side of the sun, its gravitational effects on other planets would be quite obvious.



ManusJustus on 25 September 2009
avinash habashi said:

how did the moon get to where it is?

Most scientists think that the moon is the result of a collision between Earth and rogue planet the size of Mars billions of years ago.  The collision would have threw large amounts of Earth's crust into orbit, and that mass eventually formed into our moon.  Since the moon and Earth's crust have similar composition, this idea is well founded.  This seems catrostrophic, but this was actually a blessing for Earth.  The moon keeps Earth's axis from tilting wildly and the collision with another 'planet' gave Earth a larger iron core resulting in a much stronger magnetic field than we should have.  Both of these make life on Earth much easier.

Also, the moon is moving farther and farther away from Earth.  This is a result of lost gravitational energy from Earth's bulge it forms with the moon (tides, but the crust moves slightly as well).  This is no concern, however, because the sun will die long before we lose the moon.



ManusJustus on 25 September 2009
dtewi said:
Why is everyone still saying the SAME thing?

Honestly, let this thread die.

I didnt say the same thing, I stated how such an orbit would be almost impossible.



dtewi on 25 September 2009
ManusJustus said:
dtewi said:
Why is everyone still saying the SAME thing?

Honestly, let this thread die.

I didnt say the same thing, I stated how such an orbit would be almost impossible.

Why don't I just edit the OP and let this be the umbrella topic for science questions?



Kimi wa ne tashika ni ano toki watashi no soba ni ita

Itsudatte itsudatte itsudatte

Sugu yoko de waratteita

Nakushitemo torimodosu kimi wo

I will never leave you