17 USC 105 provides that:
(a) In General.—Copyright protection under this title is not available for any work of the United States Government, but the United States Government is not precluded from receiving and holding copyrights transferred to it by assignment, bequest, or otherwise.
Under 17 USC 101:
A “work of the United States Government” is a work prepared by an officer or employee of the United States Government as part of that person’s official duties.
However under 17 USC 105 (b):
Subject to subsection (c), the covered author of a covered work owns the copyright to that covered work.
The definitions section of section 105 provides that "covered authors " are faculty members at any of 12 specified institutes, academies, colleges, and universities run by the Federal Government, and "covered works" are any textual works created by covered authors.
Thus to be free of copyright under section 105, a work must have been created by "an officer or employee of the United States Federal Government as part of that person’s official duties." and not by a faculty member at any of the institutions listed in 105 (d). 17 USC 105 does not apply to works by the various US state governments, nor to contractors hired by the US Federal government.
Works that are free of copyright under section 105 are in the public domain under US law, and may lawfully be used in any way at all, but it is widely considered unethical, although not unlawful, to fail to credit the source of such works, or indeed of older works long out of copyright protection. Note that such works could be protected under the laws of other countries, and such copyrights may apply outside the US.
Just because an image or text is published by a US government agency does not waive copyright, nor does the absence of a copyright notice. (Under the Berne Convention a copyright notice cannot be required for protection, and US law implements this in 17 USC 401 (a) which provides that a notice may be present.)
The web page linked in the question above includes the statement:
Video contributed by Dr. Marcelo Saba, National Institute for Space Research, Brazil
This strongly implies that Dr Saba owns the copyright, although it does not prove that. It might be owned by the Institute, or some other employee of the Institute. But Dr Saba could probably indicate who does own the copyright, and on what terms if any the image may be used.
When content is protected by copyright, a license to reproduce that content must normally be explicitly stated. The US Freedom of Information Act (FoI) has nothing to do with providing such licenses. It does not matter under US law whether the person wanting to reuse content is a citizen or resident of the US or not, the rules are the same for all. However, US government works may be protected outside the US. It is the location of use, not the nationality of the person using them, that will matter.