I find that ambient music works well. There are two YouTube channels I like. Cryo Chamber and Jedi Master.
[video=youtube;haZJ8-rq4pg]https://www.youtube.com/watch?v=haZJ8-rq4pg&list=PL1Ve2OhVEeABJA1CyxgI1xJ9RjUwXhPnJ&index=53[/video]
[video=youtube;j4aGk0W6AU4]https://www.youtube.com/watch?v=j4aGk0W6AU4&t=3304s[/video]
[video=youtube;nppDQSa0TgU]https://www.youtube.com/watch?v=nppDQSa0TgU&list=PL1Ve2OhVEeABJA1CyxgI1xJ9RjUwXhPnJ&index=68[/video]
[video=youtube;BJiLmIpEj1w]https://www.youtube.com/watch?v=BJiLmIpEj1w&list=PL1Ve2OhVEeABJA1CyxgI1xJ9RjUwXhPnJ&index=70&t=1581s[/video]
For exploring the farthest reaches of the galaxy, near permit regions, or near Guardian or Thargoid sites, Cryo Chamber has some dark ambient tracks inspired by the various Old Ones of Lovecraft.
[video=youtube;qL3osHj-Myc]https://www.youtube.com/watch?v=qL3osHj-Myc&list=PL1Ve2OhVEeABJA1CyxgI1xJ9RjUwXhPnJ&index=37[/video]
[video=youtube;X--TT1ABB_Y]https://www.youtube.com/watch?v=X--TT1ABB_Y&t=782s[/video]
I like some of the more atmospheric pop bands, too, like Sigur Ros and Radiohead:
[video=youtube;rW-QxWD3dUc]https://www.youtube.com/watch?v=rW-QxWD3dUc&list=PL1Ve2OhVEeABJA1CyxgI1xJ9RjUwXhPnJ&index=24[/video]
[video=youtube;GBVHoojL6LI]https://www.youtube.com/watch?v=GBVHoojL6LI&list=PL1Ve2OhVEeABJA1CyxgI1xJ9RjUwXhPnJ&index=18[/video]
[video=youtube;swafPlTnZeU]https://www.youtube.com/watch?v=swafPlTnZeU&list=PL1Ve2OhVEeABJA1CyxgI1xJ9RjUwXhPnJ&index=3[/video]
[video=youtube;TTAU7lLDZYU]https://www.youtube.com/watch?v=TTAU7lLDZYU&list=PL1Ve2OhVEeABJA1CyxgI1xJ9RjUwXhPnJ&index=55[/video]
[video=youtube;xnzdcRyDg94]https://www.youtube.com/watch?v=xnzdcRyDg94&list=PL1Ve2OhVEeABJA1CyxgI1xJ9RjUwXhPnJ&index=65[/video]
Pop electronic acts like the Chemical Brothers and Moby work, too:
[video=youtube;HPofeXuIDqA]https://www.youtube.com/watch?v=HPofeXuIDqA&list=PL1Ve2OhVEeABJA1CyxgI1xJ9RjUwXhPnJ&index=21[/video]
[video=youtube;HqzBSy_7tZc]https://www.youtube.com/watch?v=HqzBSy_7tZc&index=6&list=PLA2BA5B17D2D1FBAE[/video]
[video=youtube;yLcr2sUwKrY]https://www.youtube.com/watch?v=yLcr2sUwKrY&list=PL1Ve2OhVEeABJA1CyxgI1xJ9RjUwXhPnJ&index=23[/video]
Of course some movie soundtracks work well, too. The Interstellar soundtrack of course, and other films like Sunshine and Blade Runner work well.
[video=youtube;pR_5QRO6kPM]https://www.youtube.com/watch?v=pR_5QRO6kPM&list=PL1Ve2OhVEeABJA1CyxgI1xJ9RjUwXhPnJ&index=4[/video]
I find this one works well when I find something really special, or when I return home after months in the black:
[video=youtube;aKPeK0AVhQs]https://www.youtube.com/watch?v=aKPeK0AVhQs&list=PL1Ve2OhVEeABJA1CyxgI1xJ9RjUwXhPnJ&index=9[/video]
Of course there are a million other great choices. Sometimes just any good music works. I love Bowie to turn up the mood after all the synthetic dark ambient:
[video=youtube;cXt-e4sjB_4]https://www.youtube.com/watch?v=cXt-e4sjB_4[/video]