Goldstone Radio Telescope (Station 14):
Specialist 1: We just received two 15-min broadcasts...104 rapid pulses. After a 0:05 interval, 44 pulses. Another f break & 30 pulses. 60 seconds of silence & then a new set of numbers. 40, break five. 36, break five. 10. 104 rapid pulses...Wait 60 seconds and the whole doggone thing repeats.
Specialist 2: Where are these signals coming from?
S1: Right in the neighborhood. Light travel time, roughly 0:07. It's well within the plane of the #ecliptic.

If the #moon is really #earth ejecta, does the fact that its orbit is closer to the plane of the #ecliptic than the #equator mean the earth's orbit was less inclined when it was ejected? Perhaps it was that collision that caused it to tilt as far as it does to begin with?

The standard reference frame for the #sun's apparent movement across the sky is called the #ecliptic; this is the apparent path from one northward #equinox to the next.

By convention, the northward equinox is considered to like it 0° of the ecliptic, the northern #solstice at 90°, the southward equinox at 180°, and the southern solstice at 270°.

3/

All this time I thought that the sun's angular velocity along the epicycle was measured relative to a line from Earth the the sun's apogee (taking the anomalistic orbit as the reference frame, rather than the #zodiac or the #ecliptic), but it turns out it's actually measured relative to a line joining the centre of Earth to the centre of the sun.

#Astronomy #Jyotisha #HistoryOfAstronomy

Being in the high desert in #Oregon (3400ft above sea level) has given me a whole new appreciation for the #ecliptic - that is, the path that the sun travels through the sky.

In July, it rose due east of my house, and set past the Blue Mountains a bit north.

Now, I watch it rise AND set far to the south of us. 1/2

Thanks @markmccaughrean This make completely sense. I also hope that very time-critical events can still be scheduled. I imagine the kind of limitation it gives (do not point in the #ecliptic towards the direction of the L2 orbit around the #Sun).

One of my 2 event is actually in May and towards the direction of the orbit, so that gives me an extra argument to get the time for the other event (the first of them). ☺️

The upcoming #NASA #Roman mission could do such s survey, perhaps focusing on a small area of the #ecliptic close to the #Galactic Centre where's there's a lot of stars. Such a survey would harvest a lot of exciting exoplanet science in itself, quite apart from the #SETI objective.

It'll be interesting to see if we find evidence for anyone out there. If they're game theorists, our chance of success may be better than we think.

End of thread.

It's exciting that the #BreakthroughListen #SETI survey is monitoring for signals from #stars on the #ecliptic plane, though it's not focusing on transiting systems specifically. #NASAs #TESS transit mission is also looking for transiting planets on the ecliptic plane, though it may not have sufficient sensitivity to the most common stars in our #Galaxy, which are quite faint. (13/n)

So, i #proposed in a paper that we should conduct a #survey for potential habitable transiting planets around more mass stars that are located close to the #ecliptic plane. Previous studies had already noted that #star systems near the ecliptic, the plane of #Earth's orbit of the #Sun, would be able to view the Earth in #transit.

Such a survey would give a short list of mutually detectable targets. We can then listen or look out for signals from them. (12/n)
https://iopscience.iop.org/article/10.3847/1538-3881/abcc5f

Right then. So take stock time in my planning for tomorrow...

#Weather looks good, if a bit windy.

#Moon is pretty bright, but stays to the east until well after midnight.

I have a list of #constellations to focus on & a line up of planets to work through.

So initial plan is to start by sweeping East along the #ecliptic to bag the planets, then go back to look at some deep sky & then finally finish with the moon.

Next it is time to hit the books and more detailed star charts

#Astrodon

This is extremely rare. The probability that a #planet with an orbital period of 1.5yr is transiting in front of its #star is ~0.5%. So, having 5 planets with such long orbital period transiting is already super interesting. For comparison, it is impossible to observe the 8 #planets of the #SolarSystem because they have relatively large mutual inclination (~2º) which would make only a few of them transiting as seen by a lucky alien observer near the #ecliptic plane.