Oumuamua...anything new here?

originally posted by: Phage
And to be clear, I have never said that Oumuamua is not an alien ship.

So you're guaranteeing that it's alien ship.

a reply to: Soylent Green Is People


Nobody can prove it's not an alien ship, but if it is, since it's very difficult to distinguish the propulsion from natural outgassing, I think it's fair to say the propulsion system is very unimpressive.

originally posted by: Riffrafter

originally posted by: Phage
a reply to: Riffrafter

2 - How was it able to increase its speed as it was leaving? Huh?!?

It didn't increase its speed. It just didn't slow down quite as much as it should have. The effect was very slight and has been attributed to outgassing.
www.abovetopsecret.com...

I hear you, Phage - but the article I read clearly said it was accelerating - not appearing to accelerate.

Also, if it's not a comet - what exactly is outgassing? Do asteroids outgas at all? It has been described as a flat, odd shaped *asteroid* by astronomers who aren't signing on with the Harvard astrophysicists. Don't shoot me - I'm only the messenger in this case, but your thoughts are appreciated as I know you're more knowledgeable than the "average bear" in these matters.

Phage is an expert on outgassing.
Phage, what say you?

originally posted by: E38Driver
a reply to: Riffrafter

Here's a link to an Arxiv preprint about it.


Could Solar Radiation Pressure Explain 'Oumuamua's Peculiar Acceleration?

They try to understand possible causes of the excess speed and examine if the acceleration could be explained even if it was an actual solar sail. Also an examination of the apparent surface color(s)... Its not a bad read.

-Driver

Thanks for the reply and the info/links. I'm going to check them out now.

originally posted by: jamespond

originally posted by: Arbitrageur

originally posted by: jamespond
Its acceleration can't be attributed to outgassing according to this link;

www.nasa.gov...

Comets normally eject large amounts of dust and gas when warmed by the Sun. But according to team scientist Olivier Hainaut of the European Southern Observatory, “there were no visible signs of outgassing from ′Oumuamua, so these forces were not expected.”

So you post a link that says this:

“This additional subtle force on ′Oumuamua likely is caused by jets of gaseous material expelled from its surface,” said Farnocchia.

And then you say "Its acceleration can't be attributed to outgassing according to this link"

Have you had your morning coffee yet?

By the way, air is more or less invisible (if there's no smog or dust in it), so just because you can't see a gas doesn't mean it's not there. So the part you quoted just means there wasn't enough particulate in the outgassing to make it visible, it doesn't mean there's no outgassing.

Ok well you should probably write into the European Southern Observatory and let them know they got it wrong. I'm sure they'll be pleased to get a bit of free schooling.

Ummm...laughing my ass off!

Thanks!

a reply to: Phage

Quote from your post - I know these are not your words:

The lack of observed dust lifted from the object by the hypothesized cometary activity can be explained by an atypical dust grain size distribution that is devoid of small grains, a low dust-to-ice ratio or surface evolution from its long journey.

Well, it can also be explained by many things that aren't observable. Like dark matter or dark energy for instance. But that doesn't mean it isn't real. Or It may be aliens having fun with air horns or something that creates gas but not any debris or ejecta? The universe of non-observable "things" approaches infinity, n'est pas?

God, I love science...especially space related science.

originally posted by: kiliker30
I think it's just a rock. Humans tend to over analyze things to fit their assumptions and agendas, that is known.

True.

And yet we live on in spite of it. Thank God for small mercies, I guess.

originally posted by: Arbitrageur
a reply to: Soylent Green Is People

Nobody can prove it's not an alien ship, but if it is, since it's very difficult to distinguish the propulsion from natural outgassing, I think it's fair to say the propulsion system is very unimpressive.

Maybe it's just in a leisurely cruise control mode right now. Fuel economy and all that...

originally posted by: Phage
a reply to: Riffrafter

2 - How was it able to increase its speed as it was leaving? Huh?!?

It didn't increase its speed. It just didn't slow down quite as much as it should have. The effect was very slight and has been attributed to outgassing.
www.abovetopsecret.com...

Phage, you obviously realise that whatever scientific explanation may arise to give a more naturalistic reason for Oumuamua and it's brief excursion into our region of space, it won't make a fig of difference.

I always appreciate your measured responses, even if I don't always agree with them.