Greetings and welcome to the
Introduction to Astronomy.
One of the things
that I like to do
in each of my introductory
astronomy classes
is to begin the class with the
Astronomy Picture of the Day.
From the NASA website that
is APOD.NASA.GOV/APOD.
And today's picture for
July the 25th of 2020.
Well, it is titled
Tianwen-1 Mission to Mars.
So what do we see here?
Well, we see a rocket lifting
up off through the atmosphere.
You can see the jets
of material that
are spewing out down below
it, which then propel
the remainder of the rocket
up out of the Earth's
gravitational field.
And it takes a significant
amount of energy
to be able to lift
something off of the earth.
So when we look at a rocket much
of what we see is actually fuel
and it takes a lot of fuel to
lift even a small payload up
into space.
And in this case, we're actually
sending a probe to Mars.
This is being
launched from China
and is going to explore Mars.
It will have an
orbiter and a lander
and a rover to really
be able to try to study
Mars in a little more detail.
Now Mars has been one of
the best studied planets
for a long time mainly because
it does show some similarities
to earth and that it has
polar caps that come and go
with the seasons and it
has a very thin atmosphere.
And it also is
known now for sure,
to have had liquid water on
it at some point in the past.
So it is really one of the
best bets in our solar system.
If we're looking for
a place where life may
have formed at some
point in the past.
Now this is not the only
mission heading towards Mars
this month, we also have one
launched by the United Arab
Emirates and NASA is launching
the Perseverance Rover as well
later this month on July
31 - That is scheduled.
So those three are
going to explore Mars.
So we should have a much
better study of Mars
over the coming months.
Now it'll take
them a little while
to get their Mars
is quite far away
and you might wonder why we're
launching so many at once.
And that is because we have
to launch at specific times.
You can't just launch at
any time to another planet.
You have to do it when it's
going to have used the least
amount of energy
otherwise it requires
even more energy and more time
to try to send things there.
So right now is the time
to send things to Mars
and what we call the
launch window to keep it
the energy down to a minimum
is coming to a close soon.
And they'll be in the next what
chance wouldn't be until 2022.
So you would not want to
delay this much longer
or you would have
to wait a couple
more years to be able to
get the craft to there.
So I am sure that we will be
able to see some nice images.
Once these do reach
Mars and give us
some more detailed
studies of the red planet.
So that was our picture of the
day for July the 25th of 2020.
It was titled Tianwen-1
Mission to Mars.
We'll be back again tomorrow
for the next picture preview
to be Hubble Ultra Deep.
So we'll see what that
is about tomorrow.
And until then, have
a great day, everyone.
And I will see you in class.
