If you are not sure if the website you want to visit is safe, you can check it out here. Enter the address (url) of the website and see the invisible elements, such as a header or meta data.
site address:astronomy.com/-/media/Images/Homepage+Elements/Flash+Promos/Circ/P30705_280x454.jpg?mw=28...
URL does not point to a web page (html/xhtml) or read error or page not found. (6404)
Url ContentHyperText Markup Language (HTML)
MIME Type / Internet Media Typetext/html
MIME Type text
File Extension.html
More Details (link to:)Wikipedia: HTML
Powered by: Very Tiny URL Shortener at https://vturl.net VeryTinyURL

Header

HTTP/1.1 404 Not Found
Content-Length 1245
Content-Type text/html
Server Microsoft-IIS/7.0
X-Powered-By ASP.NET; Sitecore CMS
Date Sun, 19 Nov 2017 23:56:12 GMT
Set-Cookie NSC_xxx.Btuspopnz.dpn_IUUQ_WJQ=ffffffffc3a0febf45525d5f4f58455e445a4a423660;path=/;httponly

Load Info

page size1245
load time (s)0.326817
redirect count0
speed download0
server IP173.226.48.53


* all occurrences of the string "http://" have been changed to "htt???/"