Someone help me:In observing the night sky it is important to judge the differences between stars and planets?

Question

Describe three ways used to distinguish between stars and planets.

It's suppose to be a paragraph essya i got this so far:

When trying to tell a star and planets apart, planets don't twinkly most of the time. Planets are closer to Earth than the stars, the planets appear as disks. Their disk like shapes disguise the twinkling effect. Unless low in the sky they might twinkle a little because, the light from planets must travel through the greatest depth of Earth's atmosphere which causes the twinkling effect.The light from a planet looks different from the light of a star it is reflected so its look more like it’s shinning steadily. Stars dont move in relation to each other from night to night. BAckround stars are sometimes referred to as the "celestial sphere". From our point of view, it looks like the starts are "painted" onto a gigantic sphere that surrongs Earth and therefore are unable to move with respect to eachother

But i was told it's much to short. I seem to have run low

Answer 1

Not bad. ("twinkle," not "twinkly").  Now that you have stated that stars don't change position relative to each other, drop the other shoe.  Explain how the planets appear to move, and why.  Make this a separate paragraph.

You might also mention that even though the diameter of the planets is what makes them less likely to twinkle, we can't resolve those diameters with the naked eye.

By the way, I don't know what you mean by a "paragraph essay," but if this is much too short, then it is going to HAVE to be more than one paragraph.

Answer 2

It's easy to flesh this out.  Don't use contractions, consider the fact that more verbose prose, while at times over the top and therefore determined by one's teacher to be eloquent ramblings to pad a paper, is good.

You also need to talk about retrograde motion (good time to mention historical context, wandering stars, etc.)

Answer 3

There's a bit of cleanup, like this:

twinkly => twinkle

BAckground => Background

I'd mention turbulence in the atmosphere for causing twinkling. It moves the image around, and magnifies it randomly.  But the disk of planets masks this effect compared to the point like stars.

You might mention that proper motion for stars is much, much slower than proper motion for planets.

You still need another effect.

The cool reflected light of planets have spectra that are very different from that of the hot stars.  You might talk about diffraction gratings or prisms that can split light into constituent colors, and how the image of a slit is repeated in each of the colors on the plate or CCD image in the spectrograph.  Then you might talk about how elements each have a characteristic spectral signature, and how the temperature of an object shows up in the peak brightness of the spectrum. Toss in a reference to black body radiation.

That should give you all three, and the extra length.  I'd make it three paragraphs, one for each concept.

Answer 4

Planets only appear as disks under telescopic examination.  Otherwise they resemble stars.  Twinkling isn't particularly helpful in determining what is a star.  Twinkling is an effect caused by the earths atmosphere.  It really doesn't have anything to do with the source.  Neither planets or stars would twinkle if seen from space.  Movement is the most reliable, and that requires many many nights of observation and record keeping.  Parallax observations can determine which is which.  Planets will show parallax with even amateur equipment.

Answer 5

the definitive test for a planet is, as the name suggests, that they change location from night to night.

teh "twinkle test" is widely quoted but is not reliable.

don't they teach ppl how to write any more? if i had handed that in when i was in school i would be in remedial english faster than i could say "split infinitive".

Answer 6

So your teacher wants a paragraph essay and you did it in two paragraphs. Looks to me like you got it nailed.