APOD: Halley Dust, Mars Dust, and Milky Way (2023 May 12)

[APOD Robot]

Halley Dust, Mars Dust, and Milky Way

Explanation: Grains of cosmic dust streaked through night skies in early May. Swept up as planet Earth plowed through the debris streams left behind by periodic Comet Halley, the annual meteor shower is known as the Eta Aquarids. This year, the Eta Aquarids peak was visually hampered by May's bright Full Moon, though. But early morning hours surrounding last May's shower of Halley dust were free of moonlight interference. In exposures recorded between April 28 and May 8 in 2022, this composited image shows nearly 90 Eta Aquarid meteors streaking from the shower's radiant in Aquarius over San Pedro de Atacama, Chile. The central Milky Way arcs above in the southern hemisphere's predawn skies. The faint band of light rising from the horizon is Zodiacal light, caused by dust scattering sunlight near our Solar System's ecliptic plane. Along the ecliptic and entrained in the Zodiacal glow are the bright planets Venus, Jupiter, Mars, and Saturn. Of course Mars itself has recently been found to be a likely source of the dust along the ecliptic responsible for creating Zodiacal light.

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[Ann]

Halley Dust, Mars Dust, and Milky Way. Image Credit & Copyright:
Petr Horalek / Institute of Physics in Opava

Yes, that's an impressive image! Even though it is a composite one! If anyone looking at today's APOD dislikes it because it is a composite, why don't you go out and take your own pictures and create a composite from them?

Anyway. I guess that the brightest light near the horizon is Venus, and the second brightest light just above Venus would be Jupiter. The rather faint red light some distance above Venus and Jupiter would be Mars, and a rather faint white light some distance above Mars would be Saturn.

Note a long and very green streak in the upper middle part of the image. This streak appears to start at a pink spot, which is the Lagoon Nebula. And then it appears to pierce an orange spot, which is Antares! How cool is that!

To the lower right of this green streak is a long bright streak that seems to "explode" in white light. Note that this meteorite leaves a reddish trail of dust.

That's cool, too!

Ann

[Rauf]

Well, I tried using Stellarium to find out which stars are which.. This is the result. If I have made a mistake, please point it out!

To the left of the Venus-Jupiter pair, we can actually see the great square of Pegasus. That was cool.

And seeing Scorpius so high in the sky is strange for me. I am living in 30 N.
I wish I could visit Chile one day

[De58te]

Looking at Stellarium for May 4th 2022, You can see that the constellation Pisces is to the left of Venus and Jupiter. Pegasus is next to Pisces.

Also noticed that in between Mars and Saturn is the constellation Aquarius. Probably explains why songs back in 1969 wrote about the dawning of the age of Aquarius. But still, even in 2022 wouldn't it still be the age of Pisces that was still rising in the east?

[Holger Nielsen]

Also visible in the image is the Maori non-constellation of The Emu, the flightless bird from New Zealand. It is made up not of stars, but of the dark clouds in the Milky Way. The head with the bill is seen near the top right and the body stretches all along the Milky Way, see also this identification. I look for it every time I see a picture of the southern Milky Way.

[orin stepanek]

I guess I was surprised that we got Mars dust! You just keep finding things out!

[johnnydeep]

So the green color of many of these meteors signifies they contain what?

From https://www.accuweather.com/en/space-news/why-do-meteors-glow-in-vibrant-colors/433610

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That is, Iron (yellow) + Magnesium (blue) = green?

[Chris Peterson]

So the green color of many of these meteors signifies they contain what?

From https://www.accuweather.com/en/space-news/why-do-meteors-glow-in-vibrant-colors/433610

---

That is, Iron (yellow) + Magnesium (blue) = green?

Only marginally. More often than not the emission of atmospheric gases is dominant. I wouldn't trust color to tell much about material unless we're seeing it split spectroscopically.

[johnnydeep]

So the green color of many of these meteors signifies they contain what?

From https://www.accuweather.com/en/space-news/why-do-meteors-glow-in-vibrant-colors/433610

---

That is, Iron (yellow) + Magnesium (blue) = green?

Only marginally. More often than not the emission of atmospheric gases is dominant. I wouldn't trust color to tell much about material unless we're seeing it split spectroscopically.

Ok, thanks.