Risu counted, which took quite a while. Then he raised his own hand, smiling a little. "It does look like we're mostly in agreement, then," he said. "Of course, without convincing evidence, we cannot pass judgement either way, but if you ask my personal opinion, there are, I would say, some fairly persuasive probabilities that make me think that there is quite a lot of activity happening in the Universe. We shall have to see, though, how scientific this is, or if it's just a feeling people have. Or, perhaps, wishful thinking."

He glanced at the students who had not raised their hands. "Any input from you, perhaps? There is no right or wrong answer to this question, as I said, but I'd be interested in your view. Are you just not persuaded? Or is there something that makes you think there is no other life at all?"

Orabelle looked aroundthe room as arms flew up. She thought about it for a minute tgeb raised her arm as well. There was a chance no matter how slim it was. It would be impossible for there to be nothing since things could mutate.... Right?

Wait! Whaa- What? What are they talking about? What are these "aliens" as muggles call them Jonathan said earlier?

Aiden decides to keep quiet. This is the first class she feels like she would get a "Troll". Not planning to drive herself out of her mind by thinking too much again, Aiden stares blankly at her desk.

Eino looked around the room and realized he was one of the few who had kept his hand down. Now he wished he had been paying more attention and raised his hand just to avoid standing out. "Ummm..." He scratched the back of his head as he struggled to answer. "I have never been to another planet so I wouldn't be able to guess if other people live on them, but if they do I should like to visit them." He finally said, which was partially true. Although, he still hadn't the slightest clue as to which planets they were talking about. "Unless... the sun is a planet, then phoenixes live on the sun, I suppose."

As the man was talking to the ones who had not raised their hands, Helena thought about it for a moment. They couldn't possibly be the only ones in this BIG universe, riiiight? And even if the tiny green creatures (with three fingers at each hand and big, black eyes, and whatever they looked like in Helena's too rich imagination) didn't exist, there had to be... some kind of life. Or maybe even humans in some other galaxies, with a more advanced technology, or whatever the muggles were calling it.

Astronomy was close, all right? THAT was the only reason this brunette had decided to show up to the class. Of course, she would remain at the BACK of the classroom and try not to make too much noise... Then the professor asked if they were not alone in the universe, and Ryden's hand went up automatically.

How could she NOT answer this question? She'd had arguments with Bridget over this topic MANY times, so the Ravenclaw felt like if she didn't answer, she'd be letting Bridget win. And Ryden NEVER let Bridget win. Ever. It was like saying Father was right, or that little kids were not annoying. It was just something that was not done.

And there WERE aliens out there. Ryden just knew it.

Kurumi giggled at Eino's answer. Not that is was a bad one, but she rather liked the idea that phoenixes lived on the sun. That would certainly explain why it was so bright and warm now wouldn't it?

However, something he said did trigger her brain to turn on and the gears to begin to turn a bit. "I am hesitant to say that there are other life forms in the universe like us," Kurumi said raising her hand timidly. "Life, well human life, requires a delicate balance of many complex things that, as far as scientists know, has only been found in perfect combination on this planet. For example, water must be in abundance for lifeforms like ourselves to survive." Of course, that doesn't disprove the existence of non-carbon based life forms.

"A visit would be something alright," Risu mused as if to himself. "The Sun is a star, incidentally, but now that you mention it, I do wonder if phoenixes could live in on it... No air or food though? I don't know." He shrugged.

"In any case, yours is a perfectly good position to take. And Miss Hollingberry," he nodded in her direction," has summed up some of the arguments very succinctly. The fact is, we don't know. We can hope or, within reason, speculate, but until we know for sure, we can't know for sure. So to speak." He smiled his little smile.

"A lot of our perceptions about what life on other planets might be like are, of course, shaped by popular culture. I specifically included bacterial life in my initial question, but what if I had asked about advanced extraterrestrial life only? Perhaps some of those who raised their hand would change their mind if I was only asking about very highly developed and sophisticated alien civilisations." He paused to give everyone a few seconds to think on that.

"Now, though," he continued, "it's time to delve into the subject in more detail. The first concept we shall discuss is the so-called 'Drake equation'." He glanced around. "Perhaps some of you have heard of this equation. It's one of the classics, so to speak, of the debate around extraterrestrial life. Very simply put, the Drake equation is a mathematical model that proposes to give you the number of civilisations in our galaxy with whom it might be possible to communicate. You enter the values for a certain amount of factors, such as the number of stars with planets and a few others, and the equation will give you the number of highly developed civilisations."

He looked at his students. "We shall look at the actual equation in a minute, but first, perhaps we can collect some of those factors ourselves. What kind of things would we have to know to form an equation like that? The number of stars with planets is one. Any other ideas? We will see if they can be found in the equation itself once we look at it, but I'd like to hear your proposals first."

Kurumi thought for a moment about this equation. It seemed...suspicious to her. How could one apply a number value to something so broad and, well, vague. "How many of those stars with planets are actually capable of supporting life?" she asked cocking her head to the side. Which made her think of another question. "Professor, on what grounds does this equation say a civilization is?"

Ryden thought for a minute, all her previous hesitations about this lesson gone. She was in study mode now and nothing would change that. The number of stars was definitely one, but life couldn't exist on stars - they were much too hot and uninhabitable. But planets...

Oh! "Professor, we would need to know how many planets there are that can hold life because not all planets can," the brunette raised her hand. What else could there be to this equation? She pushed aside the thought that this formula was completely rubbish - it was WAY too mathematical. How could it ACTUALLY be relevant? Did it work on those statistical things? Hmm.

The... Drake equation?

"Is it... the one used to calculate the number of extraterrestrial civilizations?" Helena asked, before answering professor Antares' question. "If so, I think we also need the length of time for which such civilizations release detectable signals into space." Or something like that.

Anyway, it sounded really complicated.

The sun was a star? But Eino thought stars could only shine at night... Why was the sun the opposite of other stars by shining during the day and disappearing during the night? Never mind. Class had moved on and now Professor Antares was about to make them do some sort of calculation, or something. Eino raised his hand. "We would have to know if they have plants?" Plants product oxygen and living beings need oxygen, he knew that much, so hopefully his answer wasn't too wrong and embarrassing. It made sense to him, at least. They could have to calculate how many plants they have to conclude how much oxygen they produce and how many people that amount of oxygen could sustain. There, he did some astronomy.

Oh, someone already said that. Meh.

"Professor, what about the number of stars that even HAVE planets? I mean, if this equation works on statistics and probability and stuff, then that, erm, bit of the number - the fraction of it - would be important, wouldn't it?" she asked, her hand only half raised as most of her brain was devoted to the question that had been asked.

Fractions. Ugh, she was not fond of them. Decimals were much much better to work with. Muggle maths was fun when they used decimals and things. Hehe.

Drake equation? Oohh! Zara's read about this. Quite the bookworm, that girl.

Raising her hand, she recited, Professor, it could be the average rate of star formation per year in our galaxy." She said, taking her photographic memory to action. It was what she had read exactly in the book. But I guess she'll have to understand it deeply to truly know the meaning of it.

Risu was impressed, and said so. "I'm impressed. You're a smart bunch." After only a few answers, they'd already covered almost all of the parameters in the actual equation. Pointing at another student, he wandered over to the blackboard and tapped it lightly with his wand.

"Very good, I have to say. I'll try to summarise them really quickly." Writing began to appear on the blackboard. "I offered you the number of stars with planets. Miss Hollingberry - and we will get to your question in a moment - and Miss Di Marco wanted to include the number of hospitable planets, which means planets capable of supporting life."

• Number of stars with planets
• Number of hospitable planets

"Miss Griffiths over here had another very important factor to add, the amount of new stars developing in the galaxy." He looked around at the sceptical Gryffindor. "Now, to answer your question, Miss Hollingberry. The equation doesn't offer a definition of civilisation as such, but the parameters required frame it in a certain way. The result if you multiply all these factors is the number of extraterrestrial civilisations with which we might be able to communicate. In fact, let me just add this. And the third factor we just discovered too." He turned around and tapped the blackboard again.

Calculating the number of extraterrestrial civilisations we can communicate with

• Number of stars with planets
• Number of hospitable planets
• Rate of star formation

"As far as the equation is concerned, 'civilisation' is any extraterrestrial life that is advanced enough to send out signals into space that we can detect. There are, of course, problems with this definition, if you will, but we shall examine those very soon. For now, let's collect the remaining equation factors."

Risu put his wand down on the desk. "We're about halfway there, really. We have our stars, any stars. Then we have our stars with planets, any planets. Then we have planets that are capable of supporting life. Now, can anyone guess what the remaining factors could be? I will tell you one, and perhaps you can come up with the rest - we need a value for those hospitable planets that actually do develop some kind of life on their surfaces." He raised a finger. "Planets alone are not enough, we need some kind of life on them. What else, do you think?"

Calculating the number of extraterrestrial civilisations we can communicate with

• Number of stars with planets
• Number of hospitable planets
• Rate of star formation
• Number of hospitable planets that develop any kind of life

Eugh. Mathsy stuff...NOT her friend. She hated maths, and she wouldn't of turned up if she'd of known what was happening in this lesson, but she was there now..and had no idea. At all, silently she mused to herself, she had no idea so there was no point in putting her hand up. Instead she would listen silently

"Well, there is water in the form of ice on Mars, water is a sign of life, and Venus is very similar to Earth accept it has a much greater atmosphere. I have heard some bacteria can withstand very harsh conditions. As for anything big, who knows, we have never actually been there and the cameras mules have sent to mars cannot catch everything", Chloe responded raising her hand high.

Kurumi stared blankly at the man for a moment trying to sort through everything he had just said...but her brain was turning more and more into cookie dough by the minute. Someone may as well stick her in the oven and call her done. Her brain was baked and they had only just begun the conversation.

Pushing the professor's confusing response to her question about civilization, she rubbed the back of her neck. "Perhaps...how many of those planets that support life actually produce life?" she asked with her hand only half raised this time. "A sort of fraction that deals with the potential for life..." If THAT made any sense. She wasn't sure it did.

Time to head towards that oven...

THE PROFESSOR KNEW HER NAME. o_O For a moment there, Ryden was struck silent as the thought that ANY professors here knew who she was. Would he tell Father? Oh, he MUSTN'T. She made a mental note to tell him not to.

"Well, professor, in order for us to be able to see if there are civilisations out there they have to send something out, right? Like artificial light... Or radio waves or something," she mused, her hand once again only half way up as she considered this new thought.

Simon looked at the Professor he wasn't sure about this but he would guess anyway. "Professor how about the size of the planet?" maybe he was going off on the wrong thing all together but at least he was trying and hopefully the Professor would see that.

Oh. My. Word.

Sophia scribbled down as much as she could, and tried to listen to Professor Antares at the same time. She marked things down in her book that might be able to help her, but at the same time it was also very difficult. She'd have to re-read all of this later, probably twice. She knew Astronomy would be challenging, so working hard was her only option.

She had to think for a moment before she answered the Professor.

"We need microscopic life, Professor," she started. "Each habitable planet should start out that way, like Earth. Then the life forms evolved over thousands, or millions, of years. Along with being hospitable planets, they would need an ecosystem to support the life forms. As in water, plants..." She paused. "Well, depending on how those organisms develop. They might not eat the same way we do, or even breathe the same way..."

She paused again. Other students mentioned radio waves.

"I agree with radio waves. Once they're developed enough, they'd have to figure out resources for technology."

Maybe?

Helena understood the first part of whatever professor Antares was talking about, that Drake equation, but as he went on... Helena thought he was talking in some other language again. It was just waaaay too complicated.

And... they needed something else for the equation. "Maybe... the number of stars that can support life?" The girl suggested, with her hand raised. "Or... can stars support life?" There was such a mess in her head right now.

Raising her hand again, Zara recited, "Number of those that can develop intelligent life."

Then she began to wonder how the professor knew her name. Maybe they had a list of something of the sort.

Fee listened to the professor intensly and her eyes grew a litte as he mentioned life on other plantes.MMmhh..was that possible?There surely was other life.In some sort.They just didnt know about it,like muggles didnt know about wizards.That would make sense.Coming to this conclusion the blonde raised her hand and looked around to see what the other students were doing.

Ohh there apparently were some that didnt think there was other life then on earth.But would that really make sense?The blonde hd no diea to be honest and she was really lookin forward to hear the others opnion.You know never knew how persuative they could be.

Fee raised an eyebrow at what the professor was saying.So if she got that right it was about an system to calculate how many livings there were in the universe right?!But could you really get that mathematical?After all the universe was HUGE. But why not give it a try.So the Slytherin thought about things that could be important to the equal.Well,what did a living need to survive?!"Professor can it be how far the planet is away from the sun?",she asked raising her hand,"i mean if the planet is to near there cant be any living.The sun is way to hot."


Fee seriously hadnt any ohter idea what could be important to that equal.Well they needed life on the planet.Sure but how did life develop?!That was such a though question."Doesnt life always start with bacterial material?",the blonde raised her hand.Hopefully the professor wouldnt think she was totally stupid,she just coiuldnt imagine how life started forming up.

All this stuff was a little over Riley's head, but really any sort of equation was most of the time. The Gryffindor did his best to follow along and listened to each students' suggestion and then to Professor Antares as he added them to the list.

Maybe it was just him but Riley seemed to think there was a celestial body missing so he raised his hand. "Umm, Professor. Would you need to count moons for the planets? Because perhaps a moon could possibly be able to host life." he suggested. The universe was a huge place and many things could be possible.