Occultation of Mars - May 10th

starfinder · Post by **starfinder** » Sat Apr 19, 2008 7:21 pm

I ran the OCCULT Predictions program today and it showed a predicted occultation of Mars (by the Moon) on Sat May 10th 2008, visible from Singapore.

(For the freeware, see: http://www.lunar-occultations.com/iota/occult4.htm )

I have also run The Sky planeterium software, set with Singapore as the observing location. It also shows that Mars will be occulted at around 11:04pm as seem from Singapore.

At that time though, the pair will be setting low in the west and 14 degrees above the horizon. Nevertheless, if the skies are clear, we should be able to see the occurence.

The Moon then will be waxing at 33% phase, past New. Mars will enter into the Moon's unilluminated portion from above as seen from here, so we can see it blink off.

We won't however, practically speaking, be able to see Mars emerge again because when it does so at around 12:01am, it and the Moon will only be half a degree above the horizon.

Would appreciate if someone can run another planetarium software to confirm the visibility of this event from Singapore.

Post by **weixing** » Sat Apr 19, 2008 8:01 pm

Hi,
Ya... My Star Chart and C2A Planeterium both show that the occultation of Mars by the Moon will occur at around 11pm as seen from Singapore.

Good news is that day is a Saturday, but bad news is the Moon is only 14 degree above horizon when the occultation occur... Now need to find a place with a clear view of the west sky.

Hope weather is good on that day.

Have a nice day.

Tachyon · Post by **Tachyon** » Sat Apr 19, 2008 9:21 pm

Well, the timing is the same: 23:03:26 hrs.

However, when I turn on the landscape mode, I think it will be a challenge to observe unless from Tuas beside the beach.

Clifford60 · Post by **Clifford60** » Sat Apr 19, 2008 9:49 pm

I think it is a good news for me, can watch from my kitchen, just hope that Bukit Timah Hill don't block it.

boothee · Post by **boothee** » Sun Apr 20, 2008 8:16 pm

Is there anything that we can study from that occultation ?
Tks,
boothee

starfinder · Post by **starfinder** » Tue Apr 22, 2008 12:10 pm

boothee wrote:Is there anything that we can study from that occultation ?
Tks,
boothee

Hi Boothee,

On the value of occultations in general, I have found the following passage from S&T's website, which incidentally involves Mars and the Moon:

"Records of occultations go way back. Aristotle told of the Moon covering Mars on April 4, 357 B.C. — proving that Mars was farther away than the Moon. The suddenness of star occultations offered the first proof that the Moon has no air and therefore cannot support life. If the Moon had an atmosphere, stars would gradually dim as the Moon’s edge approached them, the same way the setting Sun dims before it reaches Earth’s horizon. Scrutinizing an occultation in 1843, Friedrich Wilhelm Bessel found that a star’s light rays did not bend at the Moon’s edge by any amount he could measure, a sign that any lunar air could have no more than 1/2000 the density of Earth’s atmosphere."

http://www.skyandtelescope.com/observin ... 27016.html

See also:
"Accurate timings of planetary and asteroidal occultations can reveal fundamental new information about the size, shape, and atmosphere (if any) of the occulting body, so such timings are especially sought by IOTA. The more timings we receive from widely spaced observers, the better we can reconstruct the object's profile."

http://www.skyandtelescope.com/observin ... page=2&c=y

Now, regarding what we can learn from the occulation to take place on 10th May itself, I suppose in observing it, we can see and/or deduce convincing evidence with our own eyes that:

(1) Mars is further away than the Moon.

(2) The Moon does not have an atmosphere.

(3) Therefore, it would not be a good idea to live on either one of them.

(4) The Moon and Mars have different independent orbits, and are relatively near to the Earth compared to the stars; that's why Mars and the Moon will appear to move into each other in such a short span of time (minutes).

BTW, looking at the Moon two days ago from my room window, I managed to observe it when it was only 6 degrees above the horizon. And when it was 14 degrees, it was actually pretty high above the foreground buildings and atmosphere. Therefore, if we make the effort to get somewhere with a good unobstructed view of the sky in the WNW, we should not have too much difficulty in observing the event, as long as its not cloudy.

Another BTW, if I'm not wrong, this occultation on May 10th would be a rare Moon-planet occultation for people in Singapore. I don't think there will be many more, if any, in the next few years.

boothee · Post by **boothee** » Wed Apr 30, 2008 5:13 pm

Wow... Cool ... I see... Thanks for your kind explanation. We will check out !

Clear Skies!

boothee

** For the time being, rain falling in these days due to the cyclone

I hope it will clear on that day. **

starfinder · Post by **starfinder** » Thu May 08, 2008 10:07 am

A reminder that the occulation of Mars by the Moon is due to take place this Saturday night (10th May) at 11.03pm.

I've run the freeware Occult 4 software again, and it shows that the exact time of the occulation for Singapore will be 11:03:30 pm. Mars would be at mag 1.3, altitude 14 degrees, azimuth 292 degrees (WNW). It will enter the Moon on its dark side (phase 33%) from "above".

I will run down to the Loewen Rd giant field at around 10.30pm to set-up for the event. There is a clear view there from the road-way area across the field to the WNW above the treelines (or may have to go down a bit to the adjacent grassy area to see the WNW).

For directions to Loewen Road see: http://www.singastro.org/viewtopic.php? ... ght=loewen
and the linked picture file there. However, note that this place is practically speaking only accessible by cars, sorry. Maybe some may like to arrange for an ob session at another place, but finding one with a clear view to 14 degrees above the horizon may be difficult.

I think this may the last planetary occultation visible from Singapore for quite some time to come, so try to catch it if you can! Let's hope for clear skies.

raychan · Post by **raychan** » Thu May 08, 2008 11:45 pm

Wow...thanks for the tip !
Wondering if it will be better viewing the occultation from Sibu Kelong. Going there for fishing this Sat and will be bringing my scope there. Wife was wondering why I'm bringing the scope for fishing.....now I have a reason to tell her [smilie=info.gif]

starfinder · Post by **starfinder** » Sun May 11, 2008 11:17 am

I went down to the Loewen Road field at about 10.35pm last night. However, it was so dark and isolated there that I decided to not to observe there alone. Who knows who might be lurking around there like on this forum!

Anyway, i drove instead to the nearby Dempsey ex-barracks cluster, and finally parked in a lot where there was a clear view of the Moon.

I set up my C-5 for photography and a 80mm refractor for visual observing.

There were bands of low level clouds near the Moon. It was clear around the Moon at 10.50pm. I observed and photographed Mars very close to the Moon. However, about 5 mins before the occultation time of 11.03pm, the Moon sank into a band of clouds, and I did not manage to observe the occultation event. Arghhh! Later on at 11.10pm, the Moon sank down further and I saw the crescent minus Mars. Well, that's proof enough.

Clouds... the bane of astronomy! Someone pls invent a cloud-zapping device.