{"id":31694,"date":"2022-04-28T09:05:40","date_gmt":"2022-04-28T09:05:40","guid":{"rendered":"https:\/\/www.skyatnightmagazine.com\/?p=107795"},"modified":"2022-04-28T09:22:12","modified_gmt":"2022-04-28T09:22:12","slug":"why-im-convinced-there-is-alien-life-in-the-universe","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/why-im-convinced-there-is-alien-life-in-the-universe\/","title":{"rendered":"Why I\u2019m convinced there is alien life in the Universe"},"content":{"rendered":"

<\/p>

By Maggie Aderin-Pocock\n \t\t<\/p>

Published: Thursday, 28 April 2022 at 12:00 am<\/p>

\n\n

T<\/span>he desire to meet aliens has always been with me. But the more I have learned about the Universe, the more I believe that they are probably out there and the less I believe that I am likely to meet one.<\/p>\n

Alien life seems likely to be out there due to the numbers.<\/p>\n

Our Galaxy contains around 200 billion stars and now we are able to detect many of the exoplanets<\/a> around them.<\/p>\n

\"""\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
Hubble\u2019s eXtreme Deep Field. (Credit: NASA; ESA; G. Illingworth, D. Magee, and P. Oesch, University of California, Santa Cruz; R. Bouwens, Leiden University; and the HUDF09 Team)<\/span><\/figcaption><\/div>\n

Even if we assume that there is on average just one planet orbiting each of these stars, that means there are a whole heap of planets out there.<\/p>\n

If we scale up to the Universe, then we estimate that there are around 100 billion galaxies, so the number of planets out there is pretty mind boggling.<\/p>\n

With so many planetary options available, it seems quite likely that there is some form of life out there too.<\/p>\n

Just follow the calculations of the Drake Equation<\/a> and you\u2019ll see what I mean.<\/p>\n

Could aliens visit planet Earth?<\/strong><\/h2>\n
\"""\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
Artist\u2019s impression of dust belts surrounding Proxima Centauri. Credit: ESO\/M. Kornmesser<\/span><\/figcaption><\/div>\n

On the question of little green men visiting us from afar I am less convinced. The problem is that the Universe is very, very vast.<\/p>\n

To travel from the Sun to the nearest star Proxima Centauri<\/a> as fast as we can with current technology (Voyager speeds of 17.5km\/s), the journey would take around 76,000 years.<\/p>\n

If travelling to the nearest star is out of the question, then couldn\u2019t we just send a message at the speed of light?<\/p>\n

But as our Galaxy is around 100,000 lightyears in diameter and our nearest star is 4.28 lightyears away, conversations are likely to be slow.<\/p>\n

If aliens were contacting us, how would we know?<\/b><\/h2>\n
\"""\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
Credit: SETI Institute<\/span><\/figcaption><\/div>\n

But if aliens were trying to contact us, what would their signal look like? Well, it is likely to be in the form of radio waves.<\/p>\n

We use these to send signals across the Solar System to communicate with our space probes, and these waves are relatively undisturbed by interstellar dust and gas.<\/p>\n

The signal would need to be a persistent one, and it would need to be structured so we can discern it from the naturally occurring radio noise that is out there.<\/p>\n

These parameters could be the hallmarks of an alien communication.<\/p>\n

The only problem is that we have detected this sort of signal before.<\/p>\n

The first one was picked up by the amazing Dame Prof Jocelyn Bell Burnell when she was a PhD student in 1964.<\/p>\n

It was a bit of an anomaly until she was able to detect others.<\/p>\n

\"""\"<\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/source><\/picture><\/div>
An artist\u2019s impression of a rotating neutron star, known as a pulsar. Credit Pitris \/ Getty Images<\/span><\/figcaption><\/div>\n

They turned out to be coming from pulsars<\/a>,<\/span> super-dense remnants of supernovae<\/a> that send out beams of radio waves which sweep past our planet with incredibly accurate frequencies. Hence the pulse.<\/p>\n

If our hallmark signature for alien communication can be met by a naturally occurring pulsar then what sort of signal should we be looking for?<\/p>\n

Well, one of the other differences between a naturally occurring radio source and an artificial one is the range of frequencies that it contains.<\/p>\n

Natural signals tend to be broadband, whereas artificial ones usually have a much narrower spectrum.<\/p>\n

Couple this with the fact that a signal coming from a planet in orbit about a star will have a Doppler shift as it moves towards us and away from us in its orbit round the star, and there may be a number of ways to tell if the signal we are picking up is potentially intelligent life.<\/p>\n

Life beyond Earth? Yay or nay? Let us know by emailing contactus@skyatnightmagazine.com<\/a><\/strong><\/em><\/p>\n

This article originally appeared in the April 2015 issue of <\/strong><\/em>BBC Sky at Night Magazine<\/strong>.<\/strong><\/em><\/p><\/body><\/html>\n

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By Maggie Aderin-Pocock Published: Thursday, 28 April 2022 at 12:00 am The desire to meet aliens has always been with me. But the more I have learned about the Universe, the more I believe that they are probably out there and the less I believe that I am likely to meet one. Alien life seems […]<\/p>\n","protected":false},"author":24,"featured_media":31695,"template":"","categories":[1],"acf":{"readingTimeMinutes":"4"},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/04\/why-im-convinced-there-is-alien-life-in-the-universe.jpg",2244,1336,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/04\/why-im-convinced-there-is-alien-life-in-the-universe-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/04\/why-im-convinced-there-is-alien-life-in-the-universe-300x179.jpg",300,179,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/04\/why-im-convinced-there-is-alien-life-in-the-universe-768x457.jpg",768,457,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/04\/why-im-convinced-there-is-alien-life-in-the-universe-1024x610.jpg",800,477,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/04\/why-im-convinced-there-is-alien-life-in-the-universe-1536x914.jpg",1536,914,true],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/04\/why-im-convinced-there-is-alien-life-in-the-universe-2048x1219.jpg",2048,1219,true]},"uagb_author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"uagb_comment_info":0,"uagb_excerpt":"By Maggie Aderin-Pocock Published: Thursday, 28 April 2022 at 12:00 am The desire to meet aliens has always been with me. But the more I have learned about the Universe, the more I believe that they are probably out there and the less I believe that I am likely to meet one. Alien life seems…","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/rss_feed\/31694"}],"collection":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/rss_feed"}],"about":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/types\/rss_feed"}],"author":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/users\/24"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media\/31695"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=31694"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=31694"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}