diff --git a/commands.go b/commands.go
index 05b79a2..3057f0c 100644
--- a/commands.go
+++ b/commands.go
@@ -122,18 +122,6 @@ var scanCommand = &Command{
 		}
 		currentGame.Register(NewScan(conn.System()))
 		conn.RecordScan()
-		system := conn.System()
-		log_info("scan sent from %s", system.name)
-		for id, _ := range index {
-			if id == system.id {
-				continue
-			}
-			delay := system.LightTimeTo(index[id])
-			id2 := id
-			After(delay, func() {
-				scanSystem(id2, system.id)
-			})
-		}
 	},
 }
 
diff --git a/game.go b/game.go
index ac8669c..a591580 100644
--- a/game.go
+++ b/game.go
@@ -101,7 +101,7 @@ func (g *Game) Reset() {
 }
 
 func (g *Game) Run() {
-	ticker := time.Tick(time.Second / time.Duration(frameRate))
+	ticker := time.Tick(time.Second / time.Duration(options.frameRate))
 	for {
 		select {
 		case <-ticker:
diff --git a/main.go b/main.go
index e9e544d..4a3d664 100644
--- a/main.go
+++ b/main.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"io"
 	"log"
@@ -11,13 +12,16 @@ import (
 	"time"
 )
 
+var options struct {
+	lightSpeed float64
+	frameRate  int
+}
+
 var (
 	dataPath    = "/projects/exo/expl.speck"
 	info_log    *log.Logger
 	error_log   *log.Logger
 	currentGame *Game
-	frameRate   = 100  // frames/second
-	lightSpeed  = 0.01 // parsecs/frame
 )
 
 func log_error(template string, args ...interface{}) {
@@ -79,6 +83,7 @@ func handleConnection(conn *Connection) {
 }
 
 func main() {
+	flag.Parse()
 	dbconnect()
 	rand.Seed(time.Now().UnixNano())
 	info_log = log.New(os.Stdout, "[INFO] ", 0)
@@ -103,3 +108,8 @@ func main() {
 		go handleConnection(NewConnection(conn))
 	}
 }
+
+func init() {
+	flag.Float64Var(&options.lightSpeed, "light-speed", 0.01, "speed of light in parsecs per frame")
+	flag.IntVar(&options.frameRate, "frame-rate", 100, "frame rate, in frames per second")
+}
diff --git a/scan.go b/scan.go
index b23c40e..91f3608 100644
--- a/scan.go
+++ b/scan.go
@@ -21,6 +21,21 @@ type scanResult struct {
 	colonizedBy *Connection
 }
 
+func (r *scanResult) Empty() bool {
+	return r.players == nil && r.colonizedBy == nil
+}
+
+func (r *scanResult) playerNames() []string {
+	if r.players == nil {
+		return nil
+	}
+	names := make([]string, 0, len(r.players))
+	for conn := range r.players {
+		names = append(names, conn.PlayerName())
+	}
+	return names
+}
+
 func NewScan(origin *System) *scan {
 	return &scan{
 		origin:  origin,
@@ -30,7 +45,7 @@ func NewScan(origin *System) *scan {
 }
 
 func (s *scan) Tick(frame int64) {
-	s.dist += lightSpeed
+	s.dist += options.lightSpeed
 	s.hits()
 	s.echos()
 }
@@ -55,6 +70,7 @@ func (s *scan) hits() {
 }
 
 func (s *scan) hitSystem(sys *System, dist float64) scanResult {
+	sys.NotifyInhabitants("scan detected from %s\n", s.origin.Label())
 	r := scanResult{
 		system:      sys,
 		colonizedBy: sys.colonizedBy,
@@ -76,5 +92,17 @@ func (s *scan) echos() {
 			break
 		}
 		log_info("echo from %v reached origin %v after %v", res.system.name, s.origin.name, time.Since(s.start))
+		if res.Empty() {
+			continue
+		}
+		s.origin.NotifyInhabitants("results from scan of %s:\n", res.system.Label())
+		s.origin.NotifyInhabitants("\tdistance: %v\n", s.origin.DistanceTo(res.system))
+		inhabitants := res.playerNames()
+		if inhabitants != nil {
+			s.origin.NotifyInhabitants("\tinhabitants: %v\n", inhabitants)
+		}
+		if res.colonizedBy != nil {
+			s.origin.NotifyInhabitants("\tcolonized by: %v\n", res.colonizedBy.PlayerName())
+		}
 	}
 }
diff --git a/system.go b/system.go
index a217e56..3b26385 100644
--- a/system.go
+++ b/system.go
@@ -44,6 +44,12 @@ func (s *System) Leave(p *Connection) {
 	p.location = nil
 }
 
+func (s *System) NotifyInhabitants(template string, args ...interface{}) {
+	s.EachConn(func(conn *Connection) {
+		fmt.Fprintf(conn, template, args...)
+	})
+}
+
 func (s *System) EachConn(fn func(*Connection)) {
 	if s.players == nil {
 		return
@@ -154,6 +160,11 @@ func bombNotice(to_id, from_id int) {
 	})
 }
 
+// for players to read.
+func (s System) Label() string {
+	return fmt.Sprintf("%s (id: %v)", s.name, s.id)
+}
+
 func (e System) String() string {
 	return fmt.Sprintf("<name: %s x: %v y: %v z: %v planets: %v>", e.name, e.x, e.y, e.z, e.planets)
 }