I challenge anyone who wants to believe in the extraterrestrial hypothesis for UFOs to view the following images and deny any relationship between demonology and space aliens.

Someone's going to say, Stephen, how can you put these images on your site as a Christian? Well someone has to do it. I have toyed with this idea since I first came upon a picture of Baphomet a while ago. I immediately saw a connection with space aliens and put it in my to-do basket sometime for the future. Some time later I was looking for some Christian images and once again came across another one in a list of images for Satan. So here we are. This image has very deep occult meanings as will be shown in the following quotations. Though he can appear as an angel of light it is pretty clear from the quotations that this image is a representation he has very strongly endorsed. This is about as strong as it could get. I don't believe a stronger connection could be shown than what you are about to see.
Quotes now follow...

The Sigil of the Baphomet is an inverted pentacle form, with two points pointing upwards, one downwards, and one to each side. It is the official symbol of the Church of Satan. Inside the pentacle is the image of a goat, its horns filling the upper two points, its ears filling the two lateral ones, and its mouth filling the lower one. This is Satan. The goat and pentacle theme is very old, and has its origins in alchemy.

Sigil of the Baphomet

“The symbol of Baphomet was used by the Knights Templar to represent Satan. Through the ages this symbol has been called by many different names. Among these are: The Goat of Mendes, The Goat of a Thousand Young, The Black Goat, The Judas Goat, and perhaps most appropriately, The Scapegoat.”

Symbol of Baphomet

Book of Belial: The Satanic Ritual in
"The Satanic Bible" by Anton LaVey (1969)

... from a very good source ... the Church of Satan Official Website.¹
http://www.dpjs.co.uk/baphomet.html
Note: above 2 pics added not from site.

This page also gives a link to:
Official history on the Church of Satan website:

• "The History of the Origin of the Sigil of Baphomet and its Use in the Church of Satan"

Another page, some more quotes:

Aleister Crowley

The British occultist Aleister Crowley was born about six months after the death of Eliphas Levi, causing him to believe that he was Levi’s reincarnation. Partly for this reason, Crowley was known within the O.T.O., the secret society he popularized, as “Baphomet”.

In one of his most important works, Magick, Liber ABA, Book 4, Crowley describes Baphomet as a divine androgyne:

The Devil does not exist. It is a false name invented by the Black Brothers to imply a Unity in their ignorant muddle of dispersions. A devil who had unity would be a God ... ‘The Devil’ is, historically, the God of any people that one personally dislikes ... This serpent, SATAN, is not the enemy of Man, but He who made Gods of our race, knowing Good and Evil; He bade ‘Know Thyself!’ and taught Initiation. He is ‘The Devil’ of the Book of Thoth, and His emblem is Baphomet, the Androgyne who is the hieroglyph of arcane perfection ... He is therefore Life, and Love. But moreover his letter is ayin, the Eye, so that he is Light; and his Zodiacal image is Capricornus, that leaping goat whose attribute is Liberty.

Although not technically a secret society, Anton Lavey’s Church of Satan remains an influential occult order. Founded in 1966, the organization adopted the “Sigil of Baphomet” as its official insignia.

After centuries of myths, hoaxes, propaganda and disinformation on both sides of the spectrum, can we truly answer the the original question posed by this article: “Who is Baphomet?”. Is it a symbol of Satan or of spiritual enlightenment? Is it a symbol of good or evil? The answer lies within the symbol itself: It is both.
https://vigilantcitizen.com/hidden-knowledge/whoisbaphomet/

OK you've got the idea. The emblem of Baphomet is pretty deep in the occult--a direct symbol of his satanic majesty.

THE LINK BETWEEN UFO ALIENS AND DEMONOLOGY

The left pic is supposedly the skull of a space alien. It is not real. Actually it is a novelty item available from an internet site. But it is a widely accepted view of the facial structure of these supposed space aliens.
The pic on the right is supposed to be of an actual space alien. May be real or not. But is also a good representation.

There is some controversy over whether Baphomet really was actually used by the Knights Templar or originally referred to the Devil. The historical evolution of the image appears to be a rather fascinating story enveloped most likely in mysticism. Considering all this, the following quote nevertheless gives a reasonably current understanding of the symbolism:

Lévi's Baphomet is the source of the later Tarot image of the Devil in the Rider-Waite design. The concept of a downward-pointing pentagram on its forehead was enlarged upon by Lévi in his discussion (without illustration) of the Goat of Mendes arranged within such a pentagram, which he contrasted with the microcosmic man arranged within a similar but upright pentagram. The actual image of a goat in a downward-pointing pentagram first appeared in the 1897 book La Clef de la Magie Noire by Stanislas de Guaita. It was this image that was later adopted as the official symbol—called the Sigil of Baphomet—of the Church of Satan, and continues to be used among Satanists.
Baphomet, as Lévi's illustration suggests, has occasionally been portrayed as a synonym of Satan or a demon, a member of the hierarchy of Hell.
http://en.wikipedia.org/wiki/Baphomet

References:
Inverted pentacle from
http://www.dpjs.co.uk/baphomet.html
http://satanisme-et-magie.skyrock.com/2372050597-Pentagrammes.html
Baphomet pic from
https://en.wikipedia.org/wiki/Baphomet
Alien pic from http://www.alienandufopictures.com/
The original Alien skull was from
http://www.kaboodle.com/reviews/ufo-alien-skull-collectible-statue-figurine-figure-sculpture-skeleton
which now gives an error message.
A larger clearer version was found from some other site--there were quite a few sites selling these.
Well that was around 2011 and a lot has changed since then. However the skull shape used here is a well accepted shape for these so called aliens.

Notes:

1. The comment "from a very good source" is from the page quoted. We in no way indorse or approve of any site supporting Satan referred to on this page.