Entering Space

Using nuts-and-bolts engineering and a unique grasp of human history, Robert Zubrin takes us to the not-very-distant future, when our global society will branch out into the universe. From the current-day prospect of lunar bases and Mars settlements to the outer reaches of other galaxies, Zubrin delivers the most important and forward-looking work on space and the true possibilities of human exploration since Carl Sagan's Cosmos.

Sagan himself said of Zubrin's humans-to-Mars plan, "Bob Zubrin really, nearly alone, changed our thinking on this issue." With Entering Space, he takes us further, into the prospect of human expansion to the outer planets of our own solar system--and beyond.

Standard and Primary covers are widely available through general retailers. They often have higher print runs and can be cheaper, especially during sales.

In contrast, Direct Market (DM) and variant covers are primarily sold in comic shops. DM editions tend to have more limited availability and may be more valuable to collectors.

The main differences lie in artwork style, availability, price, and collector appeal. Ultimately, the choice between standard and variant covers depends on personal preference, budget, and individual collecting goals.

Comic book enthusiasts have various formats to choose from when collecting their favorite stories.
Here's a brief overview of the main types:

Omnibus

• Large, hardcover collections
• Usually contain complete runs or extensive story arcs
• Typically 800-1000+ pages
• Higher price point, often €100-€150

Oversized Hardcover (OHC)

• Similar dimensions to omnibus, but thinner
• Collect shorter runs or story arcs
• Usually 300-600 pages
• Priced between €30-€50

Hardcover (HC)

• Standard-sized hardcover books
• Collect 6-12 issues typically
• Similar dimensions to single issues, but with a hard cover
• Priced around €25-€35

Trade Paperback (TP)

• Softcover collections
• Standard comic book size
• Usually collect 4-6 issues
• Most affordable option, typically €15-€25

Other Formats

• Absolute Editions: Oversized, deluxe hardcovers (mainly DC Comics)
• Compendiums: Massive paperback collections
• Graphic Novels (OGN/GN): Original stories not previously released as single issues

The choice between these formats often depends on personal preference, budget, and collecting goals. Omnibus and OHC editions offer larger artwork and more content but at a higher price, while TPs provide a more affordable way to collect complete story arcs