The Moon will pass so close north of Mars in the night of September 5/6 that there will be an occultation: a hiding of the planet.
See the end note about enlarging illustrations.
Our dawn scene is a few hours after the occultation has happened. Their comparative heights meant that the Moon covered Mars for a track across South America and then for dawn in Africa.
The Moon happens to be at the apogee of its orbit (its most distant point from us) on Sep. 6 (at 7 by Universal Time), so it appears slightly smaller than average,
As for Mars, its winter solstice was on Sep. 4, meaning that it is receiving more sunshine on its southern hemisphere: its south pole is tilted toward us.
This survey of Mars’s changing appearance through the year is arranged from right to left because the planet moves generally eastward. Short vertical lines point to the north and south ecliptic poles; longer lines to celestial (Earth-equatorial) north and south. A stick points from the center of Mars toward the Sun. A small circle indicates Mars’s south polar icecap. now relatively shrunken because in the sunlight.
And you can see that Mars has been growing rapidly larger, as we overtake it. We will pass it at opposition on October 13.
In this space view, from 15° north of the ecliptic plane, the paths of Earth and Mars are shown for August, September, and October, with sightlines from Earth to Mars at Sep. 6 and at the date of opposition. The dashed line, with ram’s-horns symbol, is at longitude 0°, the vernal equinox direction, where the Sun appears for us on March 20, and which Earth will reach on September 22.
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ILLUSTRATIONS in these posts are made with precision but have to be inserted in another format. You may be able to enlarge them on your monitor. One way: right-click, and choose “View image”, then enlarge. Or choose “Copy image”, then put it on your desktop, then open it. On an iPad or phone, use the finger gesture that enlarges (spreading with two fingers, or tapping and dragging with three fingers). Other methods have been suggested, such as dragging the image to the desktop and opening it in other ways.
Sometimes I make improvements or corrections to a post after positing it. If you click on the title, rather than on ‘Read more’, I think you are sure to see the latest version.
This weblog maintains its right to be about astronomy or anything under the sun.
Some astronomical humor:
https://xkcd.com/2356/
I fear that we might have a lot longer wait than 2030 unless we are to believe oligarch Musk which I don’t!I think that it’s beyond the limits of present technology, just,but even if you got people there what human population could the dying ecosystem of Mars sustain? it’s too far to rely on shipments from Earth on a regular basis.sadly it’s probably our only hope beyond the Earth/Moon system.
The ecliptic and equatorial poles were a nice touch. It took awhile, but then I learned that the 2 axes would have the same direction when Mars is at 6 hr. or 18 hr. of right ascension. When viewing Mars as it migrates eastward between 18 hours R. A. and 6 hours R. A., the ecliptic axis is tilted to the right of the equatorial axis. I also didn’t realize that Mars has a gibbous shape usually. Thanks for the diagram.
It is a treat to see these illustrations. So much information conveyed so elegantly.
Is there a comet on the equator, setting in the west? Or is Zephyrus playing badminton?
One detail that was a little obscure in my picture was the Urn of Aquarius, a triangle of three stars with a fourth in the middle; this happened to be almost behind the arrow showing the movement of the sky in one hour.
Of course, it’s obvious now. Thank you.
The Moon and Mars were lovely last night, even through the haze from the wildfires.
Think that from Mars there must be times when Earth’s Moon could be seen to move in front and behind the Earth.when it moves behind the Earth there must be a noticable magnitude change due to the large size of the Moon? I’m guessing that as our Moon is not much smaller than Mercury it must be a naked eye object from Mars well if it wasn’t so close to the Earth as the light of the two probably merge.
I assume it could be figured out mathematically if our moon is visible from Mars with the naked eye. If not, we’ll have to wait until 2030 when we send astronauts to Mars.